U.S. patent number 7,291,713 [Application Number 10/470,680] was granted by the patent office on 2007-11-06 for branched polyalkylene glycols.
This patent grant is currently assigned to Kyowa Hakko Kogyo Co., Ltd.. Invention is credited to Takashi Kuwabara, Mayumi Mukai, Tatsuya Murakami, Noriko Sakurai, Toshiyuki Suzawa, Motoo Yamasaki, Kinya Yamashita.
United States Patent |
7,291,713 |
Yamasaki , et al. |
November 6, 2007 |
**Please see images for:
( Certificate of Correction ) ** |
Branched polyalkylene glycols
Abstract
The present invention provides a branched polyalkylene glycol
wherein three or more single-chain polyalkylene glycols and a group
having reactivity with an amino acid side chain, the N-terminal
amino group or the C-terminal carboxyl group in a polypeptide or a
group convertible into the group having reactivity are bound; and a
physiologically active polypeptide modified with the branched
polyalkylene glycol.
Inventors: |
Yamasaki; Motoo (Machida,
JP), Suzawa; Toshiyuki (Yamato, JP),
Murakami; Tatsuya (Tokyo, JP), Sakurai; Noriko
(Tokyo, JP), Yamashita; Kinya (Mishima,
JP), Mukai; Mayumi (Shizuoka, JP),
Kuwabara; Takashi (Shizuoka, JP) |
Assignee: |
Kyowa Hakko Kogyo Co., Ltd.
(Tokyo, JP)
|
Family
ID: |
18887145 |
Appl.
No.: |
10/470,680 |
Filed: |
January 30, 2002 |
PCT
Filed: |
January 30, 2002 |
PCT No.: |
PCT/JP02/00709 |
371(c)(1),(2),(4) Date: |
January 12, 2004 |
PCT
Pub. No.: |
WO02/060978 |
PCT
Pub. Date: |
August 08, 2002 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050063936 A1 |
Mar 24, 2005 |
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Foreign Application Priority Data
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Jan 30, 2001 [JP] |
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2001-021616 |
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Current U.S.
Class: |
530/351;
525/54.1; 548/546; 424/78.27 |
Current CPC
Class: |
A61P
5/00 (20180101); A61P 43/00 (20180101); A61K
47/641 (20170801); C08G 65/329 (20130101); A61P
3/00 (20180101); A61K 47/62 (20170801); A61P
37/04 (20180101); C08G 65/3311 (20130101); A61K
47/642 (20170801); A61K 47/60 (20170801); A61K
38/00 (20130101); C08L 2203/02 (20130101) |
Current International
Class: |
C07K
17/06 (20060101); A61K 31/765 (20060101); A61K
47/48 (20060101); C07D 207/408 (20060101) |
Field of
Search: |
;548/546 ;424/78.27
;530/351 ;525/54.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 400 486 |
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Dec 1990 |
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EP |
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0809996 |
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Dec 1997 |
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EP |
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0 839 849 |
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May 1998 |
|
EP |
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0 809 996 |
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Apr 1999 |
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EP |
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1153088 |
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Jun 1989 |
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JP |
|
2000-191700 |
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Jul 2000 |
|
JP |
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WO95/11924 |
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May 1995 |
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WO |
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WO97/10281 |
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Mar 1997 |
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WO |
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WO99/22770 |
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May 1999 |
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WO |
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WO99/45964 |
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Sep 1999 |
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WO |
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WO 99/55377 |
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Nov 1999 |
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WO |
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WO 01/48052 |
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Jul 2001 |
|
WO |
|
Other References
Conforti, et al., "PEG Superoxide Dismutase Derivatives:
Anti-Inflammatory Activity in Carrageenan Pelurisy in Rats",
Pharmacological Research Communications, vol. 19, No. 4 (1987), pp.
287-294. cited by other .
Yamasaki, et al., "Modification of Recombinant Human Granulocyte
Colony-Stimulating Factor (rhG-CSF) and Its Derivative ND 28 with
Polyethylene Glycol", J. Biochem, vol. 115, No. 5, (1994), pp.
814-819. cited by other .
Ahern, et al., ed., Stability of Protein Pharmaceuticals, Part B,
Pharmaceutical Biotechnology, vol. 3, "PEG-Modified Proteins"
(1992), pp. 235-263. cited by other .
Ohno, "Polymer-Modification and Polymer Solvent for the Protein
Stabilization", Dept. Of Biotechnology, Tokyo University of
Agriculture and Technology, vol. 38, No. 5 (1998), pp. 208-210.
cited by other .
Inada, et al., "Ester Synthesis Catalyzed by Polyethylene
Glycol-Modified Lipase in Benzene", Biochemical and Biophysical
Research Communications, vol. 122, No. 2 (1984) pp. 845-850. cited
by other .
Campbell, et al., Pegylated Peptides V, Journal of Peptide
Research, vol. 49 (1997) pp. 527-537. cited by other .
Goodson, et al., "Site-directed Pegylation of Recombinant
Interleukin-2 at its Glycosylation Site", Bio/Technology, vol. 8
(1990) pp. 343-346. cited by other .
Knauf, et al., "Relationship of Effective Molecular Size to
Systemic Clearance in Rats of Recombinant Interleukin-2 Chemically
Modified with Water-soluble Polymers", the Journal of Biological
Chemistry, vol. 263, No. 29 (1988) pp. 15064-15070. cited by other
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Pettit, et al., "Structure-Function Studies of Interleukin 15 Using
Site-Specific Mutagenesis, Polyethylene Glycol Conjugation, and
Homology Modeling", The Journal of Biological Chemistry, vol. 272,
No. 4 (1997), pp. 2312-2318. cited by other .
Zeuzem, et al., "Peginterferon alfa-2a (40 kDa) monotherapy: a
novel agent for chronic hepatitis C therapy", Expert Opin.
Investig. Drugs (2001), vol. 12, pp. 2201-2213. cited by other
.
Motzer, et al., "Phase I Trial of 40-kd Branched Pegylated
Interferon alfa-2a for Patients With Advanced Renal Cell
Carcinoma", Journal of Clinical Oncology, vol. 19, No. 5 (Mar. 1,
2001), pp. 1312-1319. cited by other.
|
Primary Examiner: McKane; Joseph K.
Assistant Examiner: Kosack; Joseph R.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
The invention claimed is:
1. A branched polyalkylene glycol represented by formula (I):
(R.sup.1-M.sub.n-X.sup.1).sub.mL(X.sup.2--X.sup.3--R.sup.2).sub.q
(I) wherein L represents ##STR00028## M represents
OCH.sub.2CH.sub.2, OCH.sub.2CH.sub.2CH.sub.2,
OCH(CH.sub.3)CH.sub.2,
(OCH.sub.2CH.sub.2).sub.r--(OCH.sub.2CH.sub.2CH.sub.2).sub.s (in
which r and s, independently represent a positive integer) or
(OCH.sub.2CH.sub.2).sub.ra--[OCH(CH.sub.3)CH.sub.2].sub.sa (in
which ra and sa independently represent a positive integer); n
represents a positive integer; m represents 3; q represents 1;
R.sup.1 represents a hydrogen atom, lower alkyl or lower alkanoyl;
R.sup.2 represents a group having reactivity with an amino acid
side chain, the N-terminal amino group or the C-terminal carboxyl
group in a polypeptide, or a group convertible into the group
having reactivity; X.sup.1 represents --CH.sub.2--NH(C.dbd.O)--;
X.sup.2 represents a bond, O or (CH.sub.2).sub.teO (in which te
represents an integer of 1 to 8); X.sup.3 represents a bond or
alkylene; and three or more R.sup.1-M.sub.n-X.sup.1's may be the
same or different, and when q is 2 or 3,
X.sup.2--X.sup.3--R.sup.2's may be the same or different.
2. The branched polyalkylene glycol according to claim 1, wherein L
is ##STR00029##
3. The branched polyalkylene glycol according to claim 1, wherein L
is ##STR00030##
4. The branched polyalkylene glycol according to claim 2 or 3,
wherein n is 10 to 100,000, and r, s, ra and sa are independently 1
to 100,000.
5. The branched polyalkylene glycol according to claim 4, wherein
R.sup.2 is a hydroxyl group, carboxy, formyl, amino, vinylsulfonyl,
mercapto, cyano, carbamoyl, halogenated carbonyl, halogenated lower
alkyl, isocyanato, isothiocyanato, oxiranyl, lower alkanoyloxy,
maleimido, succinimidooxycarbonyl, substituted or unsubstituted
aryloxycarbonyl, benzotriazolyloxycarbonyl, phthalimidooxycarbonyl,
imidazolylcarbonyl, substituted or unsubstituted lower
alkoxycarbonyloxy, substituted or unsubstituted aryloxycarbonyloxy,
tresyl, lower alkanoyloxycarbonyl, substituted or unsubstituted
aroyloxycarbonyl, substituted or unsubstituted aryldisulfido, or
azido.
6. The branched polyalkylene glycol according to claim 5, which has
a molecular weight of 500 to 1,000,000.
7. A chemically modified polypeptide comprising a physiologically
active polypeptide or its derivative containing at least one
branched polyalkylene glycol according to claim 2 or 3.
8. The chemically modified polypeptide according to claim 7,
wherein the physiologically active polypeptide is an enzyme, a
cytokine or a hormone.
9. A pharmaceutical composition comprising the chemically modified
polypeptide according to claim 8 and a pharmaceutically acceptable
carrier.
Description
This application is a filing under 35 U.S.C. 371 of PCT/JP02/00709,
which was filed Jan. 30, 2002.
TECHNICAL FIELD
The present invention relates to polyalkylene glycols having a
branched structure which are useful as modifiers for polypeptides
having a physiological activity (physiologically active
polypeptides) and to physiologically active polypeptides modified
with the polyalkylene glycols. The present invention also relates
to pharmaceutical compositions comprising the physiologically
active polypeptides modified with the polyalkylene glycols.
BACKGROUND ART
Physiologically active polypeptides are useful as therapeutic
agents for specific diseases. However, they are unstable when
administered into blood, and a sufficient pharmacological effect
can rarely be expected. For instance, physiologically active
polypeptides having a molecular weight of less than 60,000
administered into blood are mostly excreted into urine by renal
glomerular filtration, and their use as therapeutic agents is not
expected to give a significant therapeutic effect and often
requires repeated administration. Some other physiologically active
polypeptides are degraded by hydrolases and the like existing in
blood, thereby losing their physiological activities. Further, some
exogenous physiologically active polypeptides have physiological
activities effective for the treatment of diseases, but it is known
that such exogenous physiologically active polypeptides and
physiologically active polypeptides produced by recombinant DNA
techniques sometimes induce immunoreaction when administered into
blood to cause serious side-effects such as anaphylactic shock
owing to the difference in structure between them and endogenous
physiologically active polypeptides. In addition, some
physiologically active polypeptides have physical properties
unsuitable for use as therapeutic agents, e.g. poor solubility.
One of the known attempts to solve these problems in using
physiologically active polypeptides as therapeutic agents is to
chemically bind at least one molecule of an inactive polymer chain
to physiologically active polypeptides. In many cases, desirable
properties are conferred on the polypeptides or proteins by
chemically binding polyalkylene glycols such as polyethylene glycol
to them.
For example, superoxide dismutase (SOD) modified with polyethylene
glycol has a remarkably prolonged half-life in blood and shows a
durable action [Pharm. Res. Commun., Vol. 19, p. 287 (1987)]. There
is also a report of modification of granulocyte colony-stimulating
factor (G-CSF) with polyethylene glycol [J. Biochem., Vol. 115, p.
814 (1994)]. Gillian E. Francis, et al. summarized examples of
polyethylene glycol-modified polypeptides such as asparaginase,
glutaminase, adenosine deaminase and uricase [Pharm. Biotechnol.,
Vol. 3, Stability of Protein Pharmaceuticals, Part B, p. 235
(1992), Plenum Press, New York]. Further, it is known that
modification of physiologically active polypeptides with
polyalkylene glycols give effects such as enhancement of thermal
stability [Seibutsubutsuri (Biophysics), Vol. 38, p. 208 (1998)]
and solubilization in organic solvents [Biochem. Biophys. Res.
Commun.: BBRC, Vol. 122, p. 845 (1984)].
With regard to the methods for binding polyalkylene glycols to
peptides or proteins, it is known to introduce an active ester of
carboxylic acid, a maleimido group, a carbonate, cyanuric chloride,
a formyl group, an oxiranyl group or the like to an end of a
polyalkylene glycol and bind it to an amino group or a thiol group
in a polypeptide [Bioconjugate Chem., Vol. 6, p. 150 (1995)]. These
techniques include the binding of a polyethylene glycol to a
specific amino acid residue in a physiologically active
polypeptide, which causes enhancement of stability in blood without
impairing the biological activities of the peptide or protein.
Examples of the polyethylene glycol modification specific to amino
acid residues in physiologically active polypeptides include the
binding of a polyethylene glycol to the carboxyl terminus of a
growth hormone-releasing factor through norleucine as a spacer [J.
Peptide Res., Vol. 49, p. 527 (1997)] and the specific binding of a
polyethylene glycol to cysteine introduced to the 3-position of
interleukin-2 by recombinant DNA techniques [BIO/TECHNOLOGY, Vol.
8, p. 343 (1990)].
Many of the above polyalkylene glycol-modified polypeptides are
obtained by binding of linear polyalkylene glycols. However, it has
been found that binding of branched polyalkylene glycols is
preferable for obtaining chemically modified polypeptides having a
high activity. It is generally known that the durability of a
chemically modified polypeptide in blood is increased as the
molecular weight of a polyalkylene glycol is higher or the
modification ratio higher [J. Biol. Chem., Vol. 263, p. 15064
(1988)], but in some cases, the physiological activity of a
physiologically active polypeptide is impaired by raising the
modification ratio. This is partly because a specific amino group
or thiol group in the physiologically active polypeptide which is
necessary for its physiological activity is modified with a
chemical modifier. For example, it is known that the physiological
activity of interleukin-15 lowers according to the modification
ratio [J. Biol. Chem., Vol. 272, p. 2312 (1997)].
On the other hand, it is difficult to synthesize high molecular
weight polyalkylene glycols having a uniform molecular weight
distribution and a high purity. In the case of
monomethoxypolyethylene glycols, for example, contamination with
diol components as impurities is known. Accordingly, attempts have
been made to prepare high molecular weight modifiers by branching
currently available polyalkylene glycols having a narrow molecular
weight distribution and a high purity. Such attempts provide
chemically modified polypeptides having a high physiological
activity with a high durability retained even with a decreased
modification ratio. Further, it is considered that a larger part of
the surface of molecules of physiologically active polypeptides can
be covered with polyalkylene glycols by branching of the
polyalkylene glycols. For example, double-chain polyethylene glycol
derivatives prepared by using cyanuric chloride as the group having
a branched structure are known (Japanese Published Unexamined
Patent Applications Nos. 72469/91 and 95200/91). In this case, a
methoxypolyethylene glycol having an average molecular weight of
5,000 is utilized, but this compound has the problem of toxicity
due to the triazine ring. Japanese Published Unexamined Patent
Application No. 153088/89 discloses that a chemically modified
polypeptide having a high activity can be obtained from a
comb-shaped polyethylene glycol which is a copolymer of
polyethylene glycol and maleic anhydride at a lower modification
ratio compared with a linear polyethylene glycol. However, this
compound has many reactive sites for a polypeptide, which causes
impairment of the physiological activity of a physiologically
active polypeptide, and has an ununiform molecular weight
distribution. Also known are a compound having two polyethylene
glycol chains through a benzene ring prepared by using cinnamic
acid as a material (Japanese Published Unexamined Patent
Application No. 88822/91) and compounds having two polyethylene
glycol chains prepared by using lysine as a material (WO96/21469,
U.S. Pat. No. 5,643,575).
As illustrated by the above examples, compounds having two
polyalkylene glycol chains are known, but those having three or
more polyalkylene glycol chains have not been produced. Although
U.S. Pat. No. 5,643,575 suggests a three-branched, water-soluble,
non-antigenic polymer, it contains no disclosure of the method for
producing the three-branched compound or of specific examples and
provides no information about the excellent effect of the
three-branched compound.
There exists a need for a chemically modified polypeptide with
improved durability which retains the activity of the
physiologically active polypeptide and whose renal glomerular
filtration is suppressed. In order to produce the chemically
modified polypeptide exhibiting such properties, there is also a
need for a modifier with a low toxicity and an improved stability
which has an excellent molecular size-increasing effect and a
narrow and uniform molecular weight distribution.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide, as a chemical
modifier for a physiologically active polypeptide, a branched
chemical modifier having polyalkylene glycol chains which has an
excellent molecular size-increasing effect. Another object of the
present invention is to provide a physiologically active
polypeptide modified with the branched polyalkylene glycol.
The present inventors made intensive studies on branched
polyalkylene glycol modifying reagents having a novel structure for
modification of physiologically active polypeptides. As a result,
the inventors have found that modifying reagents having a molecular
size-increasing effect superior to that of known linear or
double-chain polyalkylene glycols can be obtained by preparing
modifiers having three or more polyalkylene glycol chains. They
have further found that modification of physiologically active
polypeptides with the above branched polyalkylene glycols gives
physiologically active polypeptides modified with branched
polyalkylene glycols having three or more chains whose renal
glomerular filtration is suppressed to a degree beyond expectation
and whose durability in blood is remarkably improved compared with
those modified with known linear or double-chain polyalkylene
glycols, while retaining their physiological activities.
It has thus been found that the above branched polyalkylene glycols
are excellent chemical modifiers and the present invention has been
completed.
That is, the present invention provides a branched polyalkylene
glycol wherein three or more single-chain polyalkylene glycols and
a group having reactivity with an amino acid side chain, the
N-terminal amino group or the C-terminal carboxyl group in a
polypeptide or a group convertible into the group having reactivity
are bound sumultaneously; a physiologically active polypeptide or
its derivative modified with the polyalkylene glycol; and a
pharmaceutical composition or a therapeutic agent comprising the
physiologically active polypeptide or its derivative modified with
the polyalkylene glycol. From another viewpoint, the present
invention relates to a chemically modified polypeptide wherein a
physiologically active polypeptide or its derivative is modified
with at least one polyalkylene glycol mentioned above directly or
through a spacer; and a pharmaceutical composition or a therapeutic
agent comprising the chemically modified polypeptide.
The present invention is described in detail below.
The branched polyalkylene glycols of the present invention include
any branched polyalkylene glycols wherein three or more
single-chain polyalkylene glycols and a group having reactivity
with an amino acid side chain, the N-terminal amino group or the
C-terminal carboxyl group in a polypeptide or a group convertible
into the group having reactivity are bound. Preferred branched
polyalkylene glycols are those wherein three or more single-chain
polyalkylene glycols and one to three groups having reactivity with
an amino acid side chain, the N-terminal amino group or the
C-terminal carboxyl group in a polypeptide or one to three groups
convertible into the groups having reactivity are bound. More
preferred are branched polyalkylene glycols wherein three or four
single-chain polyalkylene glycols and one group having reactivity
with an amino acid side chain, the N-terminal amino group or the
C-terminal carboxyl group in a polypeptide or one group convertible
into the group having reactivity are bound.
The single-chain polyalkylene glycol may be any single-chain
polyalkylene glycol but is preferably R.sup.1-M.sub.n-X.sup.1 (in
which M, n, R.sup.1 and X.sup.1 have the same meanings as defined
below).
The group having reactivity with an amino acid side chain, the
N-terminal amino group or the C-terminal carboxyl group in a
polypeptide or a group convertible into the group having reactivity
may be any group having reactivity with an amino acid side chain,
the N-terminal amino group or the C-terminal carboxyl group in a
polypeptide or any group convertible into the group having
reactivity.
Preferred branched polyalkylene glycols of the present invention
include compounds represented by formula (I):
(R.sup.1-M.sub.n-X.sup.1).sub.mL(X.sup.2--X.sup.3--R.sup.2).sub.q
(I) {wherein L represents a group capable of having four or more
branches; M represents OCH.sub.2CH.sub.2,
OCH.sub.2CH.sub.2CH.sub.2, OCH(CH.sub.3)CH.sub.2,
(OCH.sub.2CH.sub.2).sub.r--(OCH.sub.2CH.sub.2CH.sub.2).sub.s (in
which r and s, which may be the same or different, each represent
an arbitrary positive integer) or
(OCH.sub.2CH.sub.2).sub.ra--[OCH(CH.sub.3) CH.sub.2].sub.sa (in
which ra and sa have the same meanings as the above r and s,
respectively); n represents an arbitrary positive integer; m
represents an integer of 3 or more; q represents an integer of 1 to
3; R.sup.1 represents a hydrogen atom, lower alkyl or lower
alkanoyl; R.sup.2 represents a group having reactivity with an
amino acid side chain, the N-terminal amino group or the C-terminal
carboxyl group in a polypeptide or a group convertible into the
group having reactivity; X.sup.1 represents a bond, O, S, alkylene,
O(CH.sub.2).sub.ta (in which ta represents an integer of 1 to 8),
(CH.sub.2).sub.tbO (in which tb has the same meaning as the above
ta), NR.sup.3 (in which R.sup.3 represents a hydrogen atom or lower
alkyl), R.sup.4--NH--C(.dbd.O)--R.sup.5 [in which R.sup.4
represents a bond, alkylene or O(CH.sub.2).sub.tc (in which tc has
the same meaning as the above ta) and R.sup.5 represents a bond,
alkylene or OR.sup.5a (in which R.sup.5a represents a bond or
alkylene)], R.sup.6--C(.dbd.O)--NH--R.sup.7 [in which R.sup.6
represents a bond, alkylene or R.sup.6aO (in which R.sup.6a has the
same meaning as the above R.sup.5a) and R.sup.7 represents a bond,
alkylene or (CH.sub.2).sub.tdO (in which td has the same meaning as
the above ta)], R.sup.8--C(.dbd.O)--O (in which R.sup.8 has the
same meaning as the above R.sup.5a) or O--C(.dbd.O)--R.sup.9 (in
which R.sup.9 has the same meaning as the above R.sup.5a); X.sup.2
represents a bond, O or (CH.sub.2).sub.teO (in which te has the
same meaning as the above ta); X.sup.3 represents a bond or
alkylene; and three or more R.sup.1-M.sub.n-X.sup.1's may be the
same or different, and when two or three
X.sup.2--X.sup.3--R.sup.2's are present (when q is 2 or 3), they
may be the same or different} [hereinafter the compounds
represented by formula (I) are referred to as Compounds (I), and
the same shall apply to the compounds of other formula
numbers].
In the definitions of the groups in formula (I), the lower alkyl
and the lower alkyl moiety of the lower alkanoyl include linear or
branched alkyl groups having 1 to 8 carbon atoms such as methyl,
ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,
tert-butyl, pentyl, neopentyl, hexyl, heptyl and octyl. The
alkylene includes alkylene groups having 1 to 8 carbon atoms such
as methylene, ethylene, n-propylene, isopropylene, n-butylene,
isobutylene, sec-butylene, tert-butylene, pentylene, neopentylene,
hexylene, heptylene and octylene.
In formula (I), M represents OCH.sub.2CH.sub.2,
OCH.sub.2CH.sub.2CH.sub.2, OCH(CH.sub.3)CH.sub.2,
(OCH.sub.2CH.sub.2).sub.r--(OCH.sub.2CH.sub.2CH.sub.2).sub.s (in
which r and s, which may be the same or different, each represent
an arbitrary positive integer) or
(OCH.sub.2CH.sub.2).sub.ra--[OCH(CH.sub.3) CH.sub.2] .sub.sa (in
which ra and sa have the same meanings as the above r and s,
respectively), and when M is
(OCH.sub.2CH.sub.2).sub.ra--(OCH.sub.2CH.sub.2CH.sub.2).sub.s (in
which r and s have the same meanings as defined above) or
(OCH.sub.2CH.sub.2).sub.ra--[OCH(CH.sub.3)CH.sub.2].sub.sa (in
which ra and sa have the same meanings as defined above), r and s,
and ra and sa are preferably 1 to 100,000, more preferably 1 to
1,000.
In formula (I), n represents an arbitrary positive integer and is
preferably 10 to 100,000, more preferably 100 to 1,000.
The average molecular weight of the polyalkylene glycol moiety
represented by M.sub.n is preferably ca. 1,000 to 1,000,000, more
preferably 5,000 to 100,000. When M.sub.n is
--(OCH.sub.2CH.sub.2).sub.n--, it is preferred that polyethylene
glycols used as starting materials are monodisperse and their
molecular weight distribution represented by Mw (weight-average
molecular weight)/Mn (number-average molecular weight) is 1.1 or
less, and commercially available ones can be utilized when those
having an average molecular weight of 30,000 or less are required.
For example, monomethoxypolyethylene glycols having an average
molecular weight of 2,000, 5,000, 10,000, 12,000, 20,000 or the
like can be used.
In formula (I), q represents an integer of 1 to 3 and is preferably
1.
In formula (I), m represents an integer of 3 or more and is
preferably 3 to 4.
The molecular weight of the branched polyalkylene glycols
represented by formula (I) is preferably in the range of 500 to
1,000,000.
In formula (I), L represents a group capable of having four or more
branches and may have a hydroxyl group, substituted or
unsubstituted lower alkyl, lower alkoxy, amino, carboxy, cyano,
formyl or the like as a substituent thereon. The lower alkyl and
the lower alkyl moiety of the lower alkoxy have the same meaning as
the above lower alkyl, and the substituent in the substituted lower
alkyl includes a hydroxyl group, amino, lower alkanoyloxy, lower
alkanoylamino, lower alkoxy, lower alkoxyalkoxy, lower alkanoyl,
lower alkoxycarbonyl, lower alkylcarbamoyl, lower alkylcarbamoyloxy
and the like. The lower alkyl moiety of the lower alkanoyloxy, the
lower alkanoylamino, the lower alkoxy, the lower alkoxyalkoxy, the
lower alkanoyl, the lower alkoxycarbonyl, the lower alkylcarbamoyl
and the lower alkylcarbamoyloxy has the same meaning as the above
lower alkyl.
As the group capable of having four or more branches represented by
L, any group can be used so far as it is capable of binding to a
group convertible into a group having reactivity with an amino acid
side chain, the N-terminal amino group or the C-terminal carboxyl
group in a polypeptide or the group having reactivity through
X.sup.2--X.sup.3, and is capable of having as branches three or
more molecules of single-chain polyalkylene glycols through
X.sup.1. Examples of L include groups formed by removing four or
more hydrogen atoms from a polyol or a polycarboxylic acid having a
molecular weight of 1,000 or less. Examples of the polyol include
low molecular compounds such as glucose, D,L-sorbitol, ribose,
erythritol, pentaerythritol, tricine
(N-[tris(hydroxymethyl)methyl]glycine), inositol, cholic acid,
3,4,5-trihydroxybenzoic acid (gallic acid), 2,4,6-trihydroxybenzoic
acid, 3,4,5-trihydroxybenzaldehyde, quinic acid, shikimic acid and
tris(hydroxymethyl)aminomethane, and stereoisomers thereof.
Examples of the polycarboxylic acid include low molecular compounds
such as 1,4,5,8-naphthalenetetracarboxylic acid, pyromellitic acid,
diethylenetriaminepentaacetic acid, 1,2,3,4-butanetetracarboxylic
acid, citric acid and .gamma.-carboxyglutamic acid, and
stereoisomers thereof.
Examples of preferred L include a group formed by removing four or
more hydrogen atoms from tricine, a group formed by removing four
or more hydrogen atoms from shikimic acid, a group formed by
removing four or more hydrogen atoms from quinic acid, a group
formed by removing four or more hydrogen atoms from erythritol, a
group formed by removing four or more hydrogen atoms from
pentaerythritol, and a group formed by removing four or more
hydrogen atoms from glucose.
The structure of the L moiety can be constructed by using a
commercially available compound as it is, using the compound
through conversion into a derivative suitable for the binding of
polyalkylene glycols according to a general organic synthetic
method, or using the compound after the protection of a functional
group [edited by The Chemical Society of Japan, Jikken Kagaku Koza
(Experimental Chemistry Course), fourth edition (1992), Organic
Synthesis I-V, Maruzen; PROTECTIVE GROUPS IN ORGANIC SYNTHESIS,
second edition, JOHN WILEY & SONS, INC. (1991); etc.]
Cyclohexanes other than those mentioned above can be synthesized
according to the method of Kihi, et al. [Daiyukikagaku (Great
Organic Chemistry), Vol. 6, p. 183 (1958), Asakura Shoten], the
method of G. E. McCasland and E. Clide Horswill [Journal of
American Chemical Society, Vol. 76, p. 2373 (1954)] or the
like.
In Compound (I), the binding of polyalkylene glycols to L through
X.sup.1 can be easily effected by combining the reactions known in
the general organic synthetic methods [edited by The Chemical
Society of Japan, Jikken Kagaku Koza (Experimental Chemistry
Course), fourth edition, pp. 19-23 (1992), Organic Synthesis I-V,
Maruzen].
In formula (I), R.sup.2 represents a group having reactivity with
an amino acid side chain, the N-terminal amino group or the
C-terminal carboxyl group in a polypeptide or a group convertible
into the group having reactivity.
Namely, the above group having reactivity includes groups reactive
with any one of the side chains of lysine, cysteine, arginine,
histidine, serine, threonine, tryptophan, aspartic acid, glutamic
acid, glutamine and the like, the N-terminal amino group and the
C-terminal carboxyl group in a polypeptide. Examples of such groups
include a hydroxyl group, carboxy, formyl, amino, vinylsulfonyl,
mercapto, cyano, carbamoyl, halogenated carbonyl, halogenated lower
alkyl, isocyanato, isothiocyanato, oxiranyl, lower alkanoyloxy,
maleimido, succinimidooxycarbonyl, substituted or unsubstituted
aryloxycarbonyl, benzotriazolyloxycarbonyl, phthalimidooxycarbonyl,
imidazolylcarbonyl, substituted or unsubstituted lower
alkoxycarbonyloxy, substituted or unsubstituted aryloxycarbonyloxy,
tresyl, lower alkanoyloxycarbonyl, substituted or unsubstituted
aroyloxycarbonyl, substituted or unsubstituted aryldisulfido, and
azido.
In the definitions of the above groups, the lower alkyl moiety of
the lower alkoxycarbonyloxy, the halogenated lower alkyl, the lower
alkanoyloxy and the lower alkanoyloxycarbonyl has the same meaning
as the above lower alkyl. The aryl moiety of the aryloxycarbonyl,
the aryloxycarbonyloxy and the aryldisulfido includes aryls having
6 to 14 carbon atoms such as phenyl, naphthyl, biphenyl and
anthryl. The aroyl moiety of the aroyloxycarbonyl includes aroyls
having 7 to 13 carbon atoms such as benzoyl, naphthoyl and
phthaloyl. The halogen moiety of the halogenated carbonyl and the
halogenated lower alkyl includes atoms of fluorine, chlorine,
bromine and iodine.
The substituted lower alkoxycarbonyloxy has 1 to 3 substituents
which may be the same or different. Examples of the substituents
are a hydroxyl group, carboxy and halogen. The halogen has the same
meaning as defined above.
The substituted aryloxycarbonyl, the substituted
aryloxycarbonyloxy, the substituted aryldisulfido and the
subsituted aroyloxycarbonyl have 1 to 3 substituents which may be
the same or different. Examples of the substituents are a hydroxyl
group, carboxy, halogen, cyano and lower alkyl. The halogen and the
lower alkyl have the same meanings as defined above,
respectively.
The group represented by R.sup.2 may be contained in the starting
material for constructing the structure of the L moiety, or may be
formed by protecting a necessary functional group in the starting
material with an appropriate protective group in advance
[PROTECTIVE GROUPS IN ORGANIC SYNTHESIS, second edition, JOHN WILEY
& SONS, INC. (1991) etc.], removing the protective group after
binding polyalkylene glycols to L through X.sup.1's to make
branches, and converting it, if necessary. Further, after
polyalkylene glycols are bound to L through X.sup.1's to make
branches, the above R.sup.2 can also be introduced to L, if
necessary through X.sup.2 or X.sup.3, by a usual organic synthetic
method.
More specifically, the branched polyalkylene glycols of the present
invention can be produced, for example, by the following processes.
The processes for producing the branched polyalkylene glycols of
the present invention are not limited thereto.
Process 1: Production of compounds wherein X.sup.1 is a bond, O,
alkylene, O(CH.sub.2).sub.ta or (CH.sub.2).sub.tbO
Compound (Ia), i.e. Compound (I) wherein X.sup.1 is a bond, O,
alkylene, O(CH.sub.2).sub.ta (in which ta has the same meaning as
defined above) or (CH.sub.2).sub.tbO (in which tb has the same
meaning as defined above) can be produced, for example, by the
following process.
A polyol having three or more hydroxyl groups is dissolved or
suspended in an appropriate solvent (e.g. N,N-dimethylformamide,
dimethyl sulfoxide, toluene, tetrahydrofuran, acetonitrile or
pyridine) under anhydrous conditions, and 3 mol or more of a halide
or tosylate of a polyalkylene glycol or a monoalkyl ether or
monocarboxylate ester thereof (hereinafter, they are collectively
referred to as polyalkylene glycol A) is added thereto in the
presence of 1 to 30 mol of an appropriate base (e.g. sodium
hydride, zinc oxide, sodium hydroxide or triethylamine), followed
by reaction at -20 to 150.degree. C. for 1 hour to 10 days to
obtain a mixture containing a branched polyalkylene glycol having
three or more chains.
The polyol is selected from commercially available compounds such
as quinic acid, glucose, sorbitol, ribose, erythritol,
pentaerythritol, tricine and inositol, and compounds derived from
the commercially available compounds. Examples of the compounds
derived from the commercially available compounds include polyols
obtained by reducing polycarboxylic acid selected from
ethylenediaminetetraacetic acid, 1,2,4,5-benzenetetracarboxylic
acid, .gamma.-carboxyglutamic acid and the like with an appropriate
reducing agent according to a usual organic synthetic method
[edited by The Chemical Society of Japan, Jikken Kagaku Koza
(Experimental Chemistry Course), fourth edition, Vols. 19-21
(1992), Maruzen]. Suitable reducing agents include lithium aluminum
hydride, sodium borohydride, sodium cyanoborohydride and
hydrogen.
The polyol may have hydroxyl groups at any positions and can be
used in the reaction after appropriate protection of a functional
group unnecessary for the reaction by the method described in
PROTECTIVE GROUPS IN ORGANIC SYNTHESIS, second edition, JOHN WILEY
& SONS, INC. (1991), etc. or conversion into a derivative.
The halide or tosylate of polyalkylene glycol A can readily be
produced by various methods disclosed in a review by Samuel
Zalipsky [Bioconjugate Chem., Vol. 6, p. 150 (1995)] and the like.
The halide or tosylate of polyalkylene glycol A used for the
binding may have any average molecular weight so long as the
molecular weight distribution is uniform (preferably Mw/Mn is 1.1
or less).
The obtained mixture containing a branched polyalkylene glycol
having three or more chains can be used in the next step at the
purity as it is or after purifying and isolating the branched
polyalkylene glycol having three, four, five or more chains to a
desired purity according to the number of branches by a known
method such as ion-exchange chromatography, reversed phase
chromatography, hydrophobic chromatography, two-phase partition or
recrystallization. By the above steps, some of Compounds (Iaj),
i.e. Compounds (Ia) wherein R.sup.2 is a hydroxyl group are
obtained.
On the other hand, the desired branched polyalkylene glycol having
three or more chains can also be prepared by using a polyhalide or
a polytosyl and polyalkylene glycol A. In this case, the desired
compound can be obtained by dissolving or suspending 3 molar
equivalents or more of polyalkylene glycol A in an appropriate
solvent (e.g. N,N-dimethylformamide, dimethyl sulfoxide, toluene or
tetrahydrofuran), and adding 1 molar equivalent of a polyhalide or
polytosyl thereto in the presence of 1 to 30 mol of an appropriate
base (e.g. sodium hydride, zinc oxide, sodium hydroxide or
triethylamine) per mol of polyalkylene glycol A, followed by
reaction at -20 to 150.degree. C. for 1 hour to 10 days.
The polyhalide may be a commercially available compound or may be
obtained by converting the above polyol into a halide [edited by
The Chemical Society of Japan, Jikken Kagaku Koza (Experimental
Chemistry Course), fourth edition, Vol. 19 (1992), Maruzen]. The
polytosyl can be obtained by dissolving or suspending the polyol in
an appropriate solvent (e.g. N,N-dimethylformamide, dimethyl
sulfoxide, toluene, tetrahydrofuran, acetonitrile or pyridine), and
adding thereto 1 to 3 molar equivalents (based on the hydroxyl
group) of a tosyl halide in the presence of 1 to 30 mol (based on
the hydroxyl group) of an appropriate base (e.g. sodium hydride,
zinc oxide, sodium hydroxide, triethylamine or potassium
naphthalene), followed by reaction at -20 to 150.degree. C. for 1
hour to several days.
Then, R.sup.2 is introduced into the obtained mixture containing a
branched polyalkylene glycol having three or more chains or a
compound purified therefrom. As R.sup.2, a functional group
remaining in a polyol, a polyhalide or a polytosyl can be utilized
as it is after polyalkylene glycol A or a halide or tosylate
thereof is bound to the polyol, polyhalide or polytosyl.
Alternatively, a functional group bound to a polyol is protected in
advance, and after polyalkylene glycol A or a halide or tosylate
thereof is bound, a group obtained by removing the protecting group
of the functional group may be utilized as R.sup.2. In this case,
after at least one hydroxyl group or other functional group in the
above polyol, polyhalide or polytosyl is protected with an
appropriate protective group, polyalkylene glycol A or a halide or
tosylate thereof is introduced to the other hydroxyl groups,
halogen or tosyl group moiety by the same method as above to
synthesize a compound with three or more polyalkylene glycol chains
bound, and then the functional group from which the protective
group is removed is utilized as such, or at least one of the
functional groups is converted to R.sup.2 according to the method
described below. The functional groups present in the polyol,
polyhalide or polytosyl before or after binding polyalkylene glycol
A or a halide or tosylate thereof include carboxy, amino, halogen,
cyano, formyl, carbonyl and the like, in addition to a hydroxyl
group. As for the protective groups for functional groups, suitable
protective groups for a hydroxyl group include benzyl, tert-butyl,
acetyl, benzyloxycarbonyl, tert-butyloxycarbonyl,
dimethyl-tert-butylsilyl, diphenyl-tert-butylsilyl, trimethylsilyl,
triphenylsilyl, tosyl and tetrahydropyranyl; those for amino
include methyl, ethyl, 9-fluorenylmethyloxycarbonyl,
benzyloxycarbonyl, nitrobenzyloxycarbonyl, N-phthalimido, acetyl
and tert-butyloxycarbonyl; those for carboxy include benzyl,
methyl, ethyl, tert-butyl, 9-fluorenylmethyl, methoxyethoxymethyl,
2,2,2-trichloroethyl, 2-(trimethylsilyl)ethyl, cinnamoyl, allyl and
nitrophenyl; and those for formyl include dimethyl acetal, diethyl
acetal, dibenzyl acetal and 1,3-dioxanyl [PROTECTIVE GROUPS IN
ORGANIC SYNTHESIS, second edition, JOHN WILEY & SONS, INC.
(1991)].
Examples of the polyols, polyhalides and polytosyls having a
functional group that can be utilized as R.sup.2, as such or
through introduction and removal of a protective group, and being
useful as a starting material for constructing the structure of the
L moiety include shikimic acid, quinic acid,
3,4,5-trihydroxybenzoic acid, cholic acid, and halides and
tosylates thereof.
Among Compounds (I), those obtained by introducing substituent
R.sup.2 into compounds having L can readily be produced, for
example, by the following processes.
Process 1-1
Among Compounds (Ia), those wherein R.sup.2 is carboxy, i.e.
compounds represented by formula (Iaa):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--COOH).sub.q
(Iaa) (wherein X.sup.1a represents a bond, O, alkylene,
O(CH.sub.2).sub.ta or (CH.sub.2).sub.tbO; and R.sup.1, L, M, n, m,
q, X.sup.2 and X.sup.3 have the same meanings as defined above,
respectively); those wherein R.sup.2 is carbamoyl, i.e. compounds
represented by formula (Iab):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--CONH.sub.2).sub.q
(Iab) (wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and
X.sup.3 have the same meanings as defined above, respectively); and
those wherein R.sup.2 is cyano, i.e. compounds represented by
formula (Iac):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--CN).sub.q (Iac)
(wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and X.sup.3 have
the same meanings as defined above, respectively) can be
synthesized, for example, in the following manner.
Compound (Iaa), Compound (Iab) and Compound (Iac) can be obtained
by reacting a reaction mixture containing (Iaj), i.e. Compound (Ia)
having a hydroxyl group as R.sup.2 among Compounds (Ia) obtained by
Process 1 using a polyol, or the compound purified from the mixture
with 1 to 30 molar equivalents of acrylic acid, acrylamide,
acrylonitrile or the like in an appropriate solvent (e.g. water,
methylene chloride, toluene or tetrahydrofuran) in the presence of
a base (catalytic amount or 1 to 20%) at -20 to 150.degree. C. for
1 hour to several days. Suitable bases include potassium hydroxide,
sodium hydroxide and sodium hydride. Compound (Iaa) can also be
obtained by dissolving or suspending a reaction mixture containing
Compound (Iaj) obtained by Process 1 or the compound purified
therefrom in an appropriate solvent (e.g. N,N-dimethylformamide,
dimethyl sulfoxide, toluene or tetrahydrofuran) under anhydrous
conditions, and reacting the compound with 1 to 50 molar
equivalents of .alpha.-halogenated acetic acid ester in the
presence of 1 to 50 mol of an appropriate base (e.g. sodium
hydride, zinc oxide, sodium hydroxide or triethylamine) at -20 to
150.degree. C. for 1 hour to several days, followed by hydrolysis.
Further, Compound (Iaa) can be obtained by dissolving or suspending
Compound (Iaj) obtained by Process 1 in an appropriate solvent
(e.g. N,N-dimethylformamide, dimethyl sulfoxide, toluene or
tetrahydrofuran), and reacting the compound with 1 to 50 mol of an
activating agent (e.g. succinimidyl carbonate, p-nitrophenyl
chloroformate or carbonyldiimidazole) in the presence of 1 to 50
mol of an appropriate base (e.g. sodium hydride, zinc oxide, sodium
hydroxide or triethylamine) at -20 to 100.degree. C. for 1 hour to
10 days to activate the compound, followed by reaction with an
amino acid such as .gamma.-aminobutyric acid, glycine or
.beta.-alanine, or a derivative thereof.
It is also possible to produce Compound (Iaa) by reacting Compound
(Iaj) obtained by Process 1 with an acid anhydride such as succinic
anhydride or glutaric anhydride in the presence of the same base as
above.
Moreover, Compound (Iaa) can be obtained by, after producing
Compound (Iai), i.e. Compound (Ia) wherein R.sup.2 is halogenated
lower alkyl according to Process 1 using a polyhalide, dissolving
or suspending hydroxycarboxylate, malonate, .gamma.-aminobutyrate,
an ester of .beta.-alanine, an ester of glycine or the like in an
appropriate solvent (e.g. N,N-dimethylformamide, dimethyl
sulfoxide, toluene or tetrahydrofuran), adding Compound (Iai)
thereto in the presence of 1 to 50 mol of an appropriate base (e.g.
sodium hydride, zinc oxide, sodium hydroxide or triethylamine), and
reacting them at -20 to 150.degree. C. for 1 hour to several days,
followed by hydrolysis.
Furthermore, Compound (Iaa) can be obtained by substituting at
least one hydroxyl group or halogen of the above polyol or
polyhalide with a residue containing carboxylic acid or protected
carboxylic acid in advance, and then substituting the remaining
three or more hydroxyl groups or halogens of the polyol or
polyhalide with polyalkylene glycol A or a halide or tosylate
thereof according to the method shown in Process 1. In this case,
the introduction of the residue containing carboxylic acid or
protected carboxylic acid can be carried out in a manner similar to
the above. When carboxylic acid is protected, the protective group
is removed after the introduction of polyalkylene glycol A or a
halide or tosylate thereof into the polyol or polyhalide to form
free carboxylic acid.
The compound converted into carboxylic acid can be purified and
isolated at a desired purity according to a known method such as
anion-exchange chromatography, hydrophobic chromatography, reversed
phase chromatography, two-phase partition or recrystallization.
Process 1-2
Among Compounds (Ia), those wherein R.sup.2 is amino, i.e.
compounds represented by formula (Iad):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--NH.sub.2).sub.q
(Iad) (wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and
X.sup.3 have the same meanings as defined above, respectively) can
be obtained, for example, by treating Compound (Iac) obtained by
Process 1-1 with an appropriate reducing agent. Suitable reducing
agents include lithium aluminum hydride, sodium borohydride, sodium
cyanoborohydride and hydrogen.
Compound (Iad) can also be obtained by reacting Compound (Iai)
obtained by Process 1 or a compound wherein the halogen moiety of
Compound (Iai) is substituted with a tosyl group, with 5
equivalents to an excess amount of a diamine such as
ethylenediamine or propylenediamine in the presence of an
appropriate base.
Further, similarly to Process 1-1, Compound (Iad) can be obtained
by dissolving or suspending Compound (Iaj) in an appropriate
solvent (e.g. N,N-dimethylformamide, dimethyl sulfoxide, toluene or
tetrahydrofuran), and reacting the compound with 1 to 50 mol of an
activating agent (e.g. succinimidyl carbonate, p-nitrophenyl
chloroformate or carbonyldiimidazole) in the presence of 1 to 50
mol of an appropriate base (e.g. sodium hydride, zinc oxide, sodium
hydroxide or triethylamine) at -20 to 100.degree. C. for 1 hour to
10 days to activate the compound, followed by reaction with 1
equivalent to an excess amount of a diamine such as ethylenediamine
or propylenediamine in the presence of an appropriate base.
Furthermore, Compound (Iad) can be obtained, in accordance with the
method shown in Process 1, by introducing at least one amino or
protected amino into a compound such as a polyol used for forming L
in advance, and then substituting the remaining three or more
hydroxyl groups or halogen moieties of the compound with
polyalkylene glycol A or a halide or tosylate thereof.
Among Compounds (Ia), those wherein R.sup.2 is maleimido, i.e.
compounds represented by formula (Iae):
##STR00001## (wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and
X.sup.3 have the same meanings as defined above, respectively) can
be obtained, for example, by reacting Compound (Iad) with
N-alkoxycarbonylmaleimide in a saturated aqueous solution of sodium
hydrogencarbonate according to the method of Oskar Keller, et al.
[Helv. Chim. Acta, Vol. 58, p. 531 (1975)] or the method of Timothy
P. Kogan, et al. [Synthetic Commun., Vol. 22, p. 2417 (1992)]. As
the N-alkoxycarbonylmaleimide, N-ethoxycarbonylmaleimide and
N-methoxycarbonylmaleimide can be used.
Compound (Iae) can also be obtained, in accordance with the method
shown in Process 1, by introducing at least one maleimido into a
compound such as a polyol used for forming L in advance, and then
substituting the remaining three or more hydroxyl groups or halogen
moieties of the compound with polyalkylene glycol A or a halide or
tosylate thereof.
Compound (Iad), Compound (Iae) and synthetic intermediates thereof
can be isolated and purified to a desired purity according to the
number of branches of polyalkylene glycol by the same methods as
above.
Process 1-3
Among Compounds (Ia), those wherein R.sup.2 is formyl, i.e.
compounds represented by formula (Iaf):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3C(.dbd.O)H).sub.q
(Iaf) (wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and
X.sup.3 have the same meanings as defined above, respectively) can
be obtained, for example, by oxidizing Compound (Iag), i.e.
Compound (Ia) having hydroxylmethyl as R.sup.2 obtained by Process
1 with an appropriate oxidizing agent. Suitable oxidizing agents
include pyridinium chlorochromate, chromic acid, silver ion and
dimethyl sulfoxide. Compound (Iaf) can also be obtained by reducing
Compound (Iaa) with an appropriate reducing agent in a manner
similar to the above.
Moreover, formyl can be introduced by binding aminoethyl acetal,
hydroxyethyl acetal, halogenated ethyl acetal, halogenated methyl
acetal or the like to Compound (Iaj) or Compound (Iai) obtained by
Process 1 or a compound wherein the halogen moiety of Compound
(Iai) is substituted with a tosyl group, and then removing
acetal.
Similarly, using Compound (Iaj) obtained by Process 1, formyl can
also be introduced by activating a hydroxyl group according to the
method shown in Process 1-1, binding aminoethyl acetal,
hydroxyethyl acetal or the like, and then removing acetal.
Compound (Iaf) can also be obtained, in accordance with the method
shown in Process 1, by introducing at least one aldehyde or
protected aldehyde into a compound such as a polyol used for
forming L in advance, and then substituting the remaining three or
more hydroxyl groups or halogen moieties of the compound with
polyalkylene glycol A or a halide or tosylate thereof.
Compound (Iaf) and synthetic intermediates thereof can be isolated
and purified to a desired purity according to the number of
branches of polyalkylene glycol by the same methods as above.
Process 1-4
Among Compounds (Ia), those wherein R.sup.2 is halogenated
carbonyl, i.e. compounds represented by formula (Iah):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--C(.dbd.O)-Z.sup.1).su-
b.q (Iah) (wherein Z.sup.1 represents a halogen; and R.sup.1, L, M,
n, m, q, X.sup.1a, X.sup.2 and X.sup.3 have the same meanings as
defined above, respectively) can be obtained, for example, by
heating Compound (Iaa) having carboxy as R.sup.2 in thionyl halide
or in an appropriate mixed solvent of thionyl halide and toluene,
dimethylformamide or the like in the presence of an appropriate
catalyst (e.g. pyridine or triethylamine) at 0 to 150.degree. C.
for 1 to 24 hours.
The halogen in the halogenated carbonyl has the same meaning as the
above halogen.
Process 1-5
Among Compounds (Ia), those wherein R.sup.2 is halogenated lower
alkyl, i.e. compounds represented by formula (Iai):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3-Z.sup.2).sub.q
(Iai) (wherein Z.sup.2 represents a halogenated lower alkyl; and
R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and X.sup.3 have the same
meanings as defined above, respectively) can be obtained, for
example, by heating Compound (Iaj) having a hydroxyl group as
R.sup.2 in thionyl halide or in an appropriate mixed solvent of
thionyl halide and toluene, dimethylformamide or the like in the
presence of an appropriate catalyst (e.g. pyridine or
triethylamine) at 0 to 150.degree. C. for 1 to 24 hours.
The halogen and the lower alkyl moiety in the halogenated lower
alkyl have the same meanings as defined above, respectively.
Compound (Iai) can also be obtained by reacting Compound (Iaj)
obtained by Process 1 or Compound (Iad) having amino as R.sup.2
with 5 equivalents to an excess amount of dihalogenated alkyl such
as dibromoethane or dibromopropane in the presence of an
appropriate base as described above.
Further, Compound (Iai) can be obtained, in accordance with the
method shown in Process 1 above, by introducing at least one
halogenated lower alkyl into a compound such as a polyol used for
forming L in advance, and then substituting the remaining three or
more hydroxyl groups or halogen moieties of the compound with
polyalkylene glycol A or a halide or tosylate thereof.
Compound (Iai) and synthetic intermediates thereof can be isolated
and purified to a desired purity according to the number of
branches of polyalkylene glycol by the same methods as above.
Process 1-6
Among Compounds (Ia), those wherein R.sup.2 is isocyanato, i.e.
compounds represented by formula (Iak):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--N.dbd.C.dbd.O).sub.q
(Iak) (wherein R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2 and
X.sup.3 have the same meanings as defined above, respectively) can
be obtained, for example, by reacting Compound (Iad) with phosgene
or oxalyl chloride in an appropriate solvent (e.g. toluene,
tetrahydrofuran or methylene chloride) at 0 to 150.degree. C. for 1
to 24 hours, or by reacting the compound with
N,N'-carbonyldiimidazole, followed by decomposition at room
temperature.
Compound (Iap), i.e. Compound (Ia) wherein R.sup.2 is
isothiocyanato (--N.dbd.C.dbd.S) can be produced according to the
same process as above except that thiophosgene is used in place of
phosgene.
Process 1-7
Among Compounds (Ia), those wherein R.sup.2 is
succinimidooxycarbonyl, substituted or unsubstituted
aryloxycarbonyl, benzotriazolyloxycarbonyl or
phthalimidooxycarbonyl, i.e. compounds represented by formula
(Ial):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--R.sup.2a).sub.q
(Ial) (wherein R.sup.2a represents succinimidooxycarbonyl,
substituted or unsubstituted aryloxycarbonyl,
benzotriazolyloxycarbonyl or phthalimidooxycarbonyl; and R.sup.1,
L, M, n, m, q, X.sup.1a, X.sup.2 and X.sup.3 have the same meanings
as defined above, respectively) can be produced by ordinary methods
for synthesizing esters.
For example, the desired compound can be obtained by reacting 1 mol
of Compound (Iaa) with 1 to 10 mol of N-hydroxysuccinimide,
substituted or unsubstituted hydroxyaryl, N-hydroxybenzotriazole or
N-hydroxyphthalimide in the presence of 1 to 10 mol of a condensing
agent (e.g. N,N'-dicyclohexylcarbodiimide) in an appropriate
solvent (e.g. dimethylformamide, methylene chloride or dimethyl
sulfoxide) at -20 to 100.degree. C. for 1 to 24 hours. More
specifically, the desired compound can be obtained according to the
method of introducing a carboxyl group to an end of polyalkylene
glycol, the method of producing N-hydroxysuccinimide ester of
carboxymethylpolyalkylene glycol, or the like by A. Fradet, et al.
[Polym. Bull., Vol. 4, p. 205 (1981)] or K. Geckeler, et al.
[Polym. Bull., Vol. 1, p. 691 (1979)].
The substituted or unsubstituted aryloxycarbonyl has the same
meaning as defined above. The aryl moiety of the hydroxyaryl has
the same meaning as the aryl moiety of the aryloxycarbonyl, and the
substituent in the substituted hydroxyaryl has the same meaning as
the substituent in the substituted aryloxycarbonyl.
Process 1-8
Among Compounds (Ia), those wherein R.sup.2 is vinylsulfonyl, i.e.
compounds represented by formula (Iam):
(R.sup.1-M.sub.n-X.sup.1a).sub.mL(X.sup.2--X.sup.3--SO.sub.2--CH.dbd.CH.s-
ub.2).sub.q (Iam) (wherein R.sup.1, L, M, n, m, q, X.sup.1a,
X.sup.2 and X.sup.3 have the same meanings as defined above,
respectively) can be produced, for example, by the method of
Margherita Morpurgo, et al. [Bioconjugate Chem., Vol. 7, p. 363
(1996)] using Compound (Iaj). Process 1-9
Among Compounds (Ia), those wherein R.sup.2 is substituted or
unsubstituted lower alkoxycarbonyloxy or substituted or
unsubstituted aryloxycarbonyloxy, i.e. compounds represented by
formula (Ian):
(R.sup.1-M.sub.n-X.sub.1a).sub.mL(X.sup.2--X.sup.3--R.sup.2b) (Ian)
(wherein R.sup.2b represents substituted or unsubstituted lower
alkoxycarbonyloxy or substituted or unsubstituted
aryloxycarbonyloxy; and R.sup.1, L, M, n, m, q, X.sup.1a, X.sup.2
and X.sup.3 have the same meanings as defined above, respectively)
can be obtained, for example, by reacting Compound (Iaj) having a
hydroxyl group as R.sup.2 with an excess amount of p-nitrophenyl
chloroformate, ethyl chloroformate or the like in the presence of a
base (e.g. dimethylaminopyridine or triethylamine) according to the
method of Talia Miron and Meir Wilchek [Bioconjugate Chem., Vol. 4,
p. 568 (1993)].
Compound (Ian) can also be obtained, in accordance with the method
shown in Process 1, by introducing at least one substituted or
unsubstituted alkoxycarbonyloxy or substituted or unsubstituted
aryloxycarbonyloxy into a compound such as a polyol used for
forming L in advance, and then substituting the remaining three or
more hydroxyl groups or halogen moieties of the compound with
polyalkylene glycol A or a halide or tosylate thereof.
Compound (Ian) and synthetic intermediates thereof can be isolated
and purified to a desired purity according to the number of
branches of polyalkylene glycol by the same methods as above.
The substituted or unsubstituted lower alkoxycarbonyloxy and the
substituted or unsubstituted aryloxycarbonyloxy have the same
meanings as defined above, respectively.
Process 2: Compounds wherein X.sup.1 is S
Compound (Ib), i.e. Compound (I) wherein X.sup.1 is S can be
obtained, for example, in a manner similar to that in Process 1, by
reacting a compound obtained by converting a polyol into a
polyhalide [edited by The Chemical Society of Japan, Jikken Kagaku
Koza (Experimental Chemistry Course), fourth edition, Vol. 19
(1992), Maruzen] or a commercially available polyhalide with a
thiol derivative of polyalkylene glycol A in an appropriate solvent
in the presence of an appropriate base.
Compound (Ib) can also be obtained, in reverse to the above step,
by reacting a halide or tosylate of polyalkylene glycol A with a
polythiol.
The thiol derivative of polyalkylene glycol A may be a commercially
available product or may be prepared by the methods summarized by
Samuel Zalipsky, et al. [Bioconjugate Chem., Vol. 6, p. 150
(1995)].
The reaction conditions and purification conditions in each step
are similar to those in Process 1.
Process 2-1
Among Compounds (Ib), those wherein R.sup.2 is carboxy, carbamoyl,
cyano, amino, maleimido, formyl, halogenated carbonyl, halogenated
lower alkyl, isocyanato, isothiocyanato, succinimidooxycarbonyl,
substituted or unsubstituted aryloxycarbonyl,
benzotriazolyloxycarbonyl, phthalimidooxycarbonyl, vinylsulfonyl,
substituted or unsubstituted lower alkoxycarbonyloxy, or
substituted or unsubstituted aryloxycarbonyloxy can be obtained by
producing the compound wherein X.sup.1 is --S-- according to
Process 2, and then combining the methods described in Process 1-1
to Process 1-9.
Process 3: Compounds wherein X.sup.1 is NR.sup.3
Compound (Ic), i.e. Compound (I) wherein X.sup.1 is NR.sup.3 (in
which R.sup.3 has the same meaning as defined above) can be
obtained, for example, in a manner similar to that in Process 1, by
reacting a compound obtained by converting a polyol into a
polyamine or a commercially available polyamine with a halide or
tosylate of polyalkylene glycol A in an appropriate solvent in the
presence of an appropriate base.
Compound (Ic) can also be obtained by reacting an amino derivative
of polyalkylene glycol A with a polyhalide.
Moreover, Compound (Ic) can be obtained by dissolving or suspending
a polyaldehyde (1 equivalent) and an amino derivative of
polyalkylene glycol A (1 to 30 equivalents per formyl group in the
polyaldehyde) in an appropriate solvent (e.g. methanol, ethanol,
dimethylformamide, acetonitrile, dimethyl sulfoxide, water or
buffer), and reacting them in the presence of a reducing agent
(e.g. sodium cyanoborohydride or sodium borohydride; 1 to 30
equivalents per formyl group in the polyaldehyde) at -20 to
100.degree. C.
Further, Compound (Ic) can be produced by using a polyamine and an
aldehyde derivative of polyalkylene glycol A.
As the above polyaldehyde, a commercially available one may be used
as it is. Also useful are a compound obtained by oxidizing a
polyalcohol, and a compound obtained by reducing a polycarboxylic
acid. The aldehyde derivative of polyalkylene glycol A may be a
commercially available product, or may be prepared by oxidizing
alcohol at an end of polyalkylene glycol A.
The reaction conditions and purification conditions in each step
are similar to those in Process 1.
Process 3-1
Among Compounds (Ic), those wherein R.sup.2 is carboxy, carbamoyl,
cyano, amino, maleimido, formyl, halogenated carbonyl, halogenated
lower alkyl, isocyanato, isothiocyanato, succinimidooxycarbonyl,
substituted or unsubstituted aryloxycarbonyl,
benzotriazolyloxycarbonyl, phthalimidooxycarbonyl, vinylsulfonyl,
substituted or unsubstituted lower alkoxycarbonyloxy, or
substituted or unsubstituted aryloxycarbonyloxy can be obtained by
synthesizing Compound (Ic) according to Process 3, and then
combining the methods described in Process 1-1 to Process 1-9.
Process 4: Compounds wherein X.sup.1 is
R.sup.4--NH--C(.dbd.O)--R.sup.5 or
R.sup.6--C(.dbd.O)--NH--R.sup.7
Compound (Ida), i.e. Compound (I) wherein X.sup.1 is
R.sup.4--NH--C(.dbd.O)--R.sup.5 (in which R.sup.4 and R.sup.5 have
the same meanings as defined above, respectively) can be obtained,
for example, by dissolving or suspending a polycarboxylic acid
compound selected from .gamma.-carboxyglutamic acid, citric acid,
1,2,3,4-butanetetracarboxylic acid, etc. in an appropriate solvent
(e.g. N,N-dimethylformamide or dimethyl sulfoxide), adding an
alcohol compound (e.g. N-hydroxysuccinimide, N-hydroxyphthalimide,
N-hydroxybenzotriazole or p-nitrophenol; 1 to 30 equivalents per
carboxyl group in the polycarboxylic acid compound) and a
condensing agent (e.g. N,N'-dicyclohexylcarbodiimide or
benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate;
1 to 30 equivalents per carboxyl group in the polycarboxylic acid
compound), further adding an amino derivative of polyalkylene
glycol A (1 to 30 equivalents per carboxyl group in the
polycarboxylic acid compound), and reacting them according to a
peptide synthetic method [Izumiya, et al., Peptide Gosei no Kiso to
Jikken (Basis and Experiment of Peptide Synthesis) (1985),
Maruzen]. The reaction is carried out with stirring under anhydrous
conditions at -20 to 100.degree. C. for 1 hour to 10 days.
It is also possible to obtain a reaction mixture containing a
branched polyethylene glycol derivative having three or more chains
wherein R.sup.2 is carboxy at a high purity by protecting at least
one carboxyl group in a polycarboxylic acid molecule with an
appropriate protective group (e.g. methyl, ethyl, benzyl or
tert-butyl), introducing an amino derivative of polyalkylene glycol
A to the remaining carboxyl groups by the above method, and then
removing the protective group of the carboxyl group by a usual
deprotection method. In this case, the introduction and removal of
the protective group of carboxylic acid can be carried out by using
methods employed in ordinary peptide synthesis [Izumiya, et al.,
Peptide Gosei no Kiso to Jikken (Basis and Experiment of Peptide
Synthesis) (1985), Maruzen]. The configuration of carboxyl groups
in the polycarboxylic acid may be any configuration including
steric configuration. The amino derivative of polyalkylene glycol A
used above may have any average molecular weight so long as the
molecular weight distribution is uniform (preferably Mw/Mn is 1.1
or less).
Compound (Idb), i.e. Compound (I) wherein X.sup.1 is
R.sup.6--C(.dbd.O)--NH--R.sup.7 (in which R.sup.6 and R.sup.7 have
the same meanings as defined above, respectively) can also be
obtained, in reverse to the above step, by reacting a polyamine
with an active ester of a carboxylic acid derivative of
polyalkylene glycol A or an acid halide derivative of polyalkylene
glycol A. The acid halide derivative of polyalkylene glycol A can
be obtained by heating a carboxylic acid derivative of polyalkylene
glycol A in thionyl halide or in an appropriate mixed solvent of
thionyl halide and toluene, dimethylformamide or the like in the
presence of an appropriate catalyst (e.g. pyridine or
triethylamine) at 0 to 150.degree. C. for 1 to 24 hours.
The reaction conditions and purification conditions in each step
are similar to those in the above processes.
Process 4-1
Among Compounds (Ida) and (Idb), those wherein R.sup.2 is carboxy,
carbamoyl, cyano, amino, maleimido, formyl, halogenated carbonyl,
halogenated lower alkyl, isocyanato, isothiocyanato,
succinimidooxycarbonyl, substituted or unsubstituted
aryloxycarbonyl, benzotriazolyloxycarbonyl, phthalimidooxycarbonyl,
vinylsulfonyl, substituted or unsubstituted lower
alkoxycarbonyloxy, or substituted or unsubstituted
aryloxycarbonyloxy can be obtained by synthesizing Compound (Ida)
or Compound (Idb) according to Process 4, and then combining the
methods described in Process 1-1 to Process 1-9.
Process 5: Compounds wherein X.sup.1 is R.sup.8--C(.dbd.O)--O or
O--C(.dbd.O)--R.sup.9
Compound (Ie), i.e. Compound (I) wherein X.sup.1 is
R.sup.8--C(.dbd.O)--O (in which R.sup.8 has the same meaning as
defined above) or O--C(.dbd.O)--R.sup.9 (in which R.sup.9 has the
same meaning as defined above) can be obtained, for example, by
dehydration condensation using a combination of polyalkylene glycol
A and a polycarboxylic acid, or a carboxylic acid derivative of
polyalkylene glycol A and a polyol. Dehydration condensation can be
carried out by dehydration in the presence of an acid or base
catalyst as in ordinary ester synthesis, or by condensing a
corresponding alcohol compound and carboxylic acid using a
condensing agent such as N,N'-dicyclohexylcarbodiimide in an
appropriate solvent (e.g. dimethylformamide, dimethyl sulfoxide,
acetonitrile, pyridine or methylene chloride). The desired compound
can also be synthesized by reacting an acid halide with a
corresponding alcohol compound in the above step.
The reaction conditions and purification conditions in each step
are similar to those in the above processes.
Process 5-1
Among Compounds (Ie), those wherein R.sup.2 is carboxy, carbamoyl,
cyano, amino, maleimido, formyl, halogenated carbonyl, halogenated
lower alkyl, isocyanato, isothiocyanato, succinimidooxycarbonyl,
substituted or unsubstituted aryloxycarbonyl,
benzotriazolyloxycarbonyl, phthalimidooxycarbonyl, vinylsulfonyl,
substituted or unsubstituted lower alkoxycarbonyloxy, or
substituted or unsubstituted aryloxycarbonyloxy can be obtained by
synthesizing Compound (Ie) according to Process 5, and then
combining the methods described in Process 1-1 to Process 1-9.
Process 6: Compounds wherein X.sup.1 is R.sup.6a--O--C(.dbd.O)--NH
or R.sup.4--NH--C(.dbd.O)--O
Compound (Ifa), i.e. Compound (I) wherein X.sup.1 is
R.sup.6a--O--C(.dbd.O)--NH (in which R.sup.6a has the same meaning
as defined above) can be produced, for example, in the following
manner.
A crude product containing Compound (Ifa) can be obtained by
reacting a commercially available polyamine or a polyamine prepared
from a polyol by a combination of the above processes with at least
3 mol of a carbonate derivative of polyalkylene glycol A. The
carbonate derivative of polyalkylene glycol A can be produced
according to the method of Talia Miron, et al. [Bioconjugate Chem.,
Vol. 4, p. 568 (1993)]. As the carbonate derivative of polyalkylene
glycol A, N-hydroxysuccinimidyl carbonate, p-nitrophenyl carbonate,
imidazolylcarbonyloxy derivative, etc. can be used.
Compound (Ifb), i.e. Compound (I) wherein X.sup.1 is
R.sup.4--NH--C(.dbd.O)--O (in which R.sup.4 has the same meaning as
defined above) can be produced, for example, in the following
manner.
Compound (Ifb) can be obtained by reacting a carbonate derivative
of a polyol with an amino derivative of polyalkylene glycol A in a
manner similar to the above.
It is also possible to selectively form Compound (Ifa) or Compound
(Ifb) by combining protection and deprotection of a functional
group according to other processes.
The reaction conditions and purification conditions in each step
are similar to those in the above processes.
Process 6-1
Among Compounds (If), those wherein R.sup.2 is carboxy, carbamoyl,
cyano, amino, maleimido, formyl, halogenated carbonyl, halogenated
lower alkyl, isocyanato, isothiocyanato, succinimidooxycarbonyl,
substituted or unsubstituted aryloxycarbonyl,
benzotriazolyloxycarbonyl, phthalimidooxycarbonyl, vinylsulfonyl,
substituted or unsubstituted lower alkoxycarbonyloxy, or
substituted or unsubstituted aryloxycarbonyloxy can be prepared by
synthesizing Compound (If) according to Process 6, and then
combining the methods described in Process 1-1 to Process 1-9.
It is also possible to obtain a single- or double-chain compound by
binding R.sup.1-M.sub.n-X.sup.1 to L, and then obtain a compound
having three or more chains by binding R.sup.1-M.sub.n-X.sup.1
which is the same or different from the above to L through similar
reaction. For example, a single- or double-chain compound is
obtained by binding polyalkylene glycol to one or two functional
groups in L by utilizing reaction selected from those shown in
Processes 1 to 6. The content of the single- or double-chain
compound formed can be controlled by changing the ratio of the
polyalkylene glycol used in the reaction to the starting material
for constructing the structure of L moiety, and thus it is possible
to produce the single- or double-chain compound as a main
component. The obtained single- or double-chain compound can be
used in the next step at the purity as it is or after purifying it
to a desired purity according to the number of branches of
polyalkylene glycol or to a high purity by the method shown in
Process 1.
A compound having three or more chains can be prepared by binding
polyalkylene glycol which is the same or different from the above
to the single- or double-chain compound obtained above according to
the method selected from those shown in Processes 1 to 6. The third
or further polyalkylene glycol may be subjected to reaction similar
to that for obtaining the single- or double-chain compound, or may
be subjected to a different reaction so as to have a different
binding mode. For example, when a compound having two or more
functional groups such as a hydroxyl group, amino and carboxy is
used as a starting material for constructing the structure of L
moiety, it is possible to first obtain a single- or double-chain
compound wherein X.sup.1 is O by the method shown in Process 1, and
then subject the third or further polyalkylene glycol to reaction
so that X.sup.1 becomes R.sup.4--NH--C(.dbd.O)--R.sup.5 by the
method shown in Process 4. As described above, a compound having
three or more chains wherein plural polyalkylene glycols are bound
to L in the same or different binding mode can be obtained by
combining Processes 1 to 6. The molecular weights of polyalkylene
glycols used in the respective reaction steps may be different, and
a desired compound can readily be obtained by using polyalkylene
glycols having different average molecular weights in the
respective reactions for binding polyalkylene glycols to L.
In the reaction for introducing polyalkylene glycols to L, it is
also possible to protect functional groups in L with appropriate
protective groups with the exception of at least one functional
group (e.g. in Process 1, at least one hydroxyl group) left
unprotected, allow L to react with polyalkylene glycols for
binding, and then remove the protective groups.
The branched polyalkylene glycols of the present invention other
than the compounds specifically shown in the above processes can
also be obtained according to processes similar to those described
above.
As described above, the polyalkylene glycols used as starting
materials in Processes 1 to 6 are commercially available, but can
also be easily produced by various methods summarized by Samuel
Zalipsky [Bioconjugate Chem., Vol. 6, p. 150 (1995)], etc.
The obtained branched polyalkylene glycols can be purified to a
desired purity according to the number of branches by methods such
as silica gel chromatography, reversed phase chromatography,
hydrophobic chromatography, ion-exchange chromatography, gel
filtration chromatography, recrystallization and extraction.
The resulting branched polyalkylene glycols can be bound to an
amino acid side chain, the N-terminal amino group or the C-terminal
carboxyl group of the above physiologically active polypeptide
directly or through a spacer.
As the spacer, amino acids and peptides are preferably used, but
other substances may also be used so long as they can bind to
polyalkylene glycols. Suitable amino acids include natural amino
acids such as lysine and cysteine, as well as ornithine,
diaminopropionic acid, homocysteine and the like. Preferred is
cysteine. Preferred peptides are those consisting of 2 to 10 amino
acid residues. The spacers other than amino acids and peptides
include glycerol, ethylene glycol and sugars. Suitable sugars
include monosaccharides and disaccharides such as glucose,
galactose, sorbose, galactosamine and lactose.
The spacer is bound to a side chain of the residue of lysine,
cysteine, arginine, histidine, serine, threonine or the like in a
physiologically active polypeptide molecule through an amide bond,
a thioether bond, an ester bond, etc., to the C-terminal carboxyl
group of the polypeptide through an amide bond or an ester bond, or
to the N-terminal amino group of the polypeptide through an amide
bond. The binding can be effected by ordinary peptide synthetic
methods [Izumiya, et al., Peptide Gosei no Kiso to Jikken (Basis
and Experiment of Peptide Synthesis) (1985), Maruzen] or
recombinant DNA techniques.
It is preferred to introduce an amino acid, a peptide or the like
as a spacer to the C-terminal carboxyl group of a physiologically
active polypeptide simultaneously with the synthesis of the
physiologically active polypeptide, but the spacer may be bound
after the synthesis of the physiologically active polypeptide. It
is also possible to activate the C-terminal carboxyl group or the
like of the polypeptide in a chemical synthetic manner and then
bind it to the spacer. Further, a spacer bound to polyalkylene
glycol in advance may be bound to a physiologically active
polypeptide by the method described above.
The physiologically active polypeptides used in the present
invention include polypeptides, antibodies, and derivatives
thereof. Examples of the polypeptides include enzymes such as
asparaginase, glutaminase, arginase, uricase, superoxide dismutase,
lactoferin, streptokinase, plasmin, adenosine deaminase,
plasminogen activator and plasminogen; cytokines such as
interleukin-1 to 18, interferon-.alpha., interferon-.beta.,
interferon-.gamma., interferon-.omega., interferon-.tau.,
granulocyte-colony stimulating factor, thrombopoietin,
erythropoietin, tumor necrosis factor, fibroblast growth factor-1
to 18, midkine, epidermal growth factor, osteogenic protein 1, stem
cell factor, vascular endothelial growth factor, transforming
growth factor and hepatocyte growth factor; hormones such as
glucagon, parathyroid hormone and glucagon like peptide; klotho
protein, angiopoietin, angiostatin, leptin, calcitonin, amylin,
insulin like growth factor 1 and endostatin.
The antibodies used in the present invention can be obtained as
polyclonal antibodies or monoclonal antibodies by using a known
method [Antibodies--A Laboratory Manual, Cold Spring Harbor
Laboratory (1988)].
The antibody used in the present invention may be either a
polyclonal antibody or a monoclonal antibody, but a monoclonal
antibody is preferred.
The monoclonal antibodies of the present invention include
antibodies produced by hybridomas, humanized antibodies, and
fragments thereof.
The humanized antibodies include human chimera antibodies and human
CDR-grafted antibodies.
By "human chimera antibodies" is meant antibodies comprising the
heavy-chain variable region (hereinafter, also referred to as HV or
VH, the heavy chain being referred to as H chain and the variable
region as V region) and the light-chain variable region
(hereinafter, also referred to as LV or VL, the light chain being
referred to as L chain) of an antibody derived from a non-human
animal, and the heavy-chain constant region (hereinafter, also
referred to as CH, the constant region being referred to as C
region) and the light-chain constant region (hereinafter, also
referred to as CL) of a human antibody. As the non-human animal,
any animal can be used so far as hybridomas can be prepared from
the animal. Suitable animals include mouse, rat, hamster and
rabbit.
By "human CDR-grafted antibodies" is meant antibodies prepared by
grafting the amino acid sequences of the CDR in the V regions of H
chain and L chain of an antibody of a non-human animal into
appropriate sites in the V regions of H chain and L chain of a
human antibody.
The antibody fragments include Fab, Fab', F(ab').sub.2,
single-chain antibodies, disulfide-stabilized V region fragments,
and peptides comprising a complementarity determining region.
Fab is a fragment with a molecular weight of about 50,000 having
antigen-binding activity constituted of about half of H chain
(N-terminal side) and the full L chain, which is obtained by
cleaving the peptide moiety above two disulfide bonds cross-linking
two H chains in the hinge regions of IgG with papain.
Fab' is a fragment with a molecular weight of about 50,000 having
antigen-binding activity, which is obtained by cleaving disulfide
bonds of the hinge regions of the above F(ab').sub.2.
F(ab').sub.2 is a fragment with a molecular weight of about 100,000
having antigen-binding activity constituted of two Fab regions
bound at the hinge regions, which is obtained by cleaving the part
below two disulfide bonds in the hinge regions of IgG with
trypsin.
The single-chain antibody (hereinafter also referred to as scFv)
refers to a VH-P-VL or VL-P-VH polypeptide in which one VH and one
VL are linked using an appropriate peptide linker (hereinafter
referred to as P). The VH and VL contained in the scFv used in the
present invention may be any of the monoclonal antibody and the
human CDR-grafted antibody of the present invention.
The disulfide-stabilized V region fragment (hereinafter also
referred to as dsFv) is a fragment in which polypeptides prepared
by substituting one amino acid residue in each of VH and VL with a
cysteine residue are linked via a disulfide bond. The amino acid
residue to be substituted with a cysteine residue can be selected
based on the prediction of the three-dimensional structure of
antibody according to the method shown by Reiter, et al. [Protein
Engineering, Vol. 7, p. 697 (1994)]. The VH and VL contained in the
disulfide-stabilized antibody of the present invention may be any
of the monoclonal antibody and the human CDR-grafted antibody.
The derivatives of the physiologically active polypeptides include
amino acid-substituted derivatives, amino acid-deleted derivatives,
sugar chain-added derivatives, sugar chain-deleted derivatives and
partial peptides.
Among the physiologically active polypeptides and derivatives
thereof described above, preferred examples include interferons
such as interferon-.beta., interferon-.alpha. and
interferon-.gamma., granulocyte-colony stimulating factor and
superoxide dismutase.
These physiologically active polypeptides can be obtained not only
by extraction from animal organs and tissues, but also by ordinary
peptide synthesis and recombinant DNA techniques. Commercially
available polypeptides can also be used.
The polypeptide used in the reaction may be a partially purified
product or a product purified to a purity suitable for chemical
modification by purification methods such as gel filtration
chromatography, ion-exchange chromatography, hydrophobic
chromatography, reversed phase chromatography and extraction.
The polypeptide is produced in a buffer such as a phosphate buffer,
a borate buffer, an acetate buffer or a citrate buffer, water, an
appropriate organic solvent such as N,N-dimethylformamide, dimethyl
sulfoxide, dioxane or tetrahydrofuran, or a mixed solvent of such
an organic solvent and an aqueous solution, and then used in
chemical modification reaction.
The branched polyalkylene glycols of the present invention can also
be used for site-specific covalent modification of polypeptides,
more specifically and preferably, all natural or recombinant
polypeptides having a free cysteine residue such as
granulocyte-colony stimulating factor (G-CSF), erythropoietin,
interferons and interleukins.
The physiologically active polypeptide modified with the branched
polyalkylene glycol of the present invention is produced by
reaction using the branched polyalkylene glycol in an amount of 1
to 1000 mol, preferably 1 to 50 mol per mol of a physiologically
active polypeptide. The degree of modification of the
physiologically active polypeptide with the branched polyalkylene
glycol can be arbitrarily selected by controlling the molar ratio
of the branched polyalkylene glycol to the physiologically active
polypeptide, reaction temperature, pH, reaction time, etc. The
solvent used in the reaction may be any of the solvents that do not
interfere with the reaction, for example, a phosphate buffer, a
borate buffer, a tris-hydrochloride buffer, an aqueous sodium
hydrogencarbonate solution, a sodium acetate buffer,
N,N-dimethylformamide, dimethyl sulfoxide, methanol, acetonitrile
and dioxane. The temperature, pH and time of the reaction are not
limited so long as the activity of the physiologically active
polypeptide is not impaired under the conditions. For example, the
reaction is preferably carried out at 0 to 50.degree. C. at pH 4 to
10 for 10 minutes to 100 hours.
The physiologically active polypeptide modified with the branched
polyalkylene glycol of the present invention can be purified by gel
filtration, ion-exchange chromatography, reversed phase high
performance liquid chromatography, affinity chromatography,
ultrafiltration or the like in a usual manner. Confirmation of the
polypeptide structure in the synthesized or purified
physiologically active polypeptide or the physiologically active
polypeptide modified with the branched polyalkylene glycol can be
carried out by mass spectrometry, nuclear magnetic resonance (NMR)
and amino acid composition analysis using an amino acid analyzer,
and also by amino acid sequence analysis by use of a gas phase
protein sequencer in which phenylthiohydantoin (PTH) amino acid
obtained by Edman degradation is analyzed by reversed phase
HPLC.
The chemically modified polypeptide of the present invention can be
administered in the form of a pharmaceutical composition for human
or animals, and the composition can be produced by ordinary methods
for producing pharmaceuticals. The methods of administration
include oral, intravenous, subcutaneous, submuscular,
intraperitoneal and percutaneous administration and other
acceptable methods, and a composition suitable for administration
can be used. The composition may comprise generally employed
additives such as an isotonizing agent, a buffer, an excipient, a
pH regulator, a stalilizer, an antiseptic, a solubilizing agent, a
wetting agent, an emulsifier, a lubricant, a sweetener, a coloring
agent and an antioxidant.
Specific examples of Compounds (I) are shown in Tables 1 and 2.
The following are supplementary explanations of the structure of
the compounds shown in Table 1. 1) In Compound 5TRC(3UA) obtained
in Example 1, the carboxyl group corresponding to
(X.sup.2--X.sup.3--R.sup.2) binds to the methylene group of
--NHCH.sub.2--. CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1]
binds to the methyleneoxy groups (--CH.sub.2O--). 2) In Compound
5SKA(3UA) obtained in Example 2, the carboxyl group corresponding
to (X.sup.2--X.sup.3--R.sup.2) binds to the 1-position of the
cyclohexene ring.
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--NH(C.dbd.O)--corresponding to
[CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1] binds to the oxygen
atoms at the 3-, 4- and 5-positions of the cyclohexene ring. 3) In
Compound 5QNA(4UA) obtained in Example 3, the carboxyl group
corresponding to (X.sup.2--X.sup.3--R.sup.2) binds to the
1-position of the cyclohexane ring, and the carboxyl group
sterically exists in the upward direction from the plane of the
figure. CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--NH(C.dbd.O)--O--
binding to the 1-position sterically exists in the downward
direction from the plane of the figure.
CH.sub.3--(OCH.sub.2CH.sub.2)--NH(C.dbd.O)--corresponding to
[CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1] binds to the oxygen
atoms at the 1-, 3-, 4- and 5-positions of the cyclohexane ring. 4)
In Compound 5PET(3UA) obtained in Example 4,
--O--(C.dbd.O)--NH(CH.sub.2).sub.3COOH corresponding to
(X.sup.2--X.sup.3--R.sup.2) binds to the methylene group
(--CH.sub.2--).
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2)--X.sup.1] binds to
the methyleneoxy groups (--CH.sub.2O--). 5) In Compound 5PET(3UM)
obtained in Example 5, the 3-maleimidopropylaminocarbonyloxy group
corresponding to (X.sup.2--X.sup.3--R.sup.2) binds to the methylene
group (--CH.sub.2--).
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1]
binds to the methyleneoxy groups (--CH.sub.2O--). 6) In Compound
5PET(3UU) obtained in Example 6, the maleimidooxycarbonyloxy group
corresponding to (X.sup.2--X.sup.3--R.sup.2) binds to the methylene
group (--CH.sub.2--).
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1]
binds to the methyleneoxy groups (--CH.sub.2O--). 7) In Compound
5PET(3URa) obtained in Example 7,
--O--(C.dbd.O)--NH(CH.sub.2).sub.3CHO corresponding to
(X.sup.2--X.sup.3--R.sup.2) binds to the methylene group
(--CH.sub.2--).
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1]
binds to the methyleneoxy groups (--CH.sub.2O--). 8) In Compound
5SUG(4UA) obtained in Example 8, the carboxyl group --O--(C.dbd.O)
corresponding to (X.sup.2--X.sup.3--R.sup.2) binds to the
oxymethylene group (--OCH.sub.2--) at the 1-position.
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH(C.dbd.O)--
corresponding to [CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1]
binds to the oxygen atoms at the 2-, 3- and 4-positions and the
methyleneoxy group at the 5-position.
TABLE-US-00001 TABLE 1
[CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1].sub.mL--(X.sup.2--X.sup.3---
R.sup.2).sub.q (I) Example No. Abbrev. X.sup.1 m L q
X.sup.2--X.sup.3--R.sup.2 15TRC(3UA) ##STR00002## 3 ##STR00003## 1
##STR00004## 25SKA(3UA) ##STR00005## 3 ##STR00006## 1 ##STR00007##
35QNA(4UA) ##STR00008## 4 ##STR00009## 1 ##STR00010## 45PET(3UA)
##STR00011## 3 ##STR00012## 1 ##STR00013## 55PET(3UM) ##STR00014##
3 ##STR00015## 1 ##STR00016## 65PET(3UU) ##STR00017## 3
##STR00018## 1 ##STR00019## 75PET(3URa) ##STR00020## 3 ##STR00021##
1 ##STR00022## 85SUG(4UA) ##STR00023## 4 ##STR00024## 1
##STR00025##
TABLE-US-00002 TABLE 2
[CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--X.sup.1].sub.mL--(X.sup.2--X.sup.3---
R.sup.2).sub.q (I) Example No. Abbrev. Structure of Compound (I)
35QNA(3UA) ##STR00026## One of R.sup.X1, R.sup.X2, R.sup.X3 and
R.sup.X4 is a hydrogen atom and the other three are
CH.sub.3--(OCH.sub.2CH.sub.2).sub.n--NH--C(.dbd.O)--. 85SUG(3UA)
##STR00027## One of R.sup.Y1, R.sup.Y2, R.sup.Y3 and R.sup.Y4 is a
hydrogen atom and the other three are
CH.sub.3--(OCH.sub.2OCH.sub.2).sub.n--CH.sub.2--NH--C(.dbd.O)--.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the blood half-life prolonging effect of chemically
modified recombinant human interferon-.beta. when intravenously
injected into mice. -.box-solid.-: change in the concentration of
unmodified rhIFN-.beta. in blood -.tangle-solidup.-: change in the
concentration of 5TRC(3UA)-rhIFN-.beta. in blood -.circle-solid.-:
change in the concentration of PEG.sub.2Lys-rhIFN-.beta. in
blood
FIG. 2 shows the blood half-life prolonging effect of chemically
modified recombinant human granulocyte-colony stimulating factors
when intravenously injected into rats. -.box-solid.-: change in the
concentration of unmodified rhG-CSF derivative in blood
-.quadrature.-: change in the concentration of unmodified rhG-CSF
in blood -.tangle-solidup.-: change in the concentration of
5SKA(3UA)-rhG-CSF derivative in blood -.DELTA.-: change in the
concentration of 5SKA(3UA)-rhG-CSF in blood -.circle-solid.-:
change in the concentration of PEG.sub.2Lys-rhG-CSF derivative in
blood -.largecircle.-: change in the concentration of
PEG.sub.2Lys-rhG-CSF in blood
BEST MODES FOR CARRYING OUT THE INVENTION
The present invention is specifically described by the following
examples, which are not to be construed as limiting the scope of
the invention. The abbreviations in the examples mean the following
unless otherwise specified. The abbreviations for amino acids and
their protective groups used herein follow the recommendations by
IUPAC-IUB Commission on Biochemical Nomenclature [Eur. J. Biochem.,
Vol. 138, p. 9 (1984)]. HPLC: high performance liquid
chromatography RI: refractive index NMR: nuclear magnetic resonance
ELISA: enzyme-linked immunosorbent assay SDS-PAGE: sodium dodecyl
sulfate-polyacrylamide gel electrophoresis PEG: poly(ethylene
glycol) mPEG: monomethoxy poly(ethylene glycol) IFN: interferon
hIFN: human interferon rhIFN: recombinant human interferon G-CSF:
granulocyte-colony stimulating factor rhG-CSF: recombinant human
granulocyte-colony stimulating factor SOD: superoxide dismutase
bSOD: bovine superoxide dismutase hSOD: human superoxide dismutase
DSC: N,N'-disuccinimidyl carbonate TEA: triethylamine DMF:
N,N-dimethylformamide DMSO: dimethyl sulfoxide NHS:
N-hydroxysuccinimide Ts: p-toluenesulfonyl TsCl: p-toluenesulfonyl
chloride DMAP: dimethylaminopyridine PyBOP:
benzotriazol-1-yloxy-tripyrrolidinophosphonium hexafluorophosphate
HOBt: N-hydroxybenzotriazole DCC: N,N'-dicyclohexylcarbodiimide
LAH: lithium aluminium hydride NMM: N-methylmorpholine TFA:
trifluoroacetic acid CDI: N,N'-carbonyldiimidazole
EXAMPLE 1
Synthesis of 5 kDa Three-chain Branched Polyethylene Glycol-tricine
Derivative
Abbreviation: 5TRC(3UA)
In 0.5 ml of DMF were dissolved 0.5 mg (2.8 .mu.mol) of tricine
(N-[Tris(hydroxymethyl)methyl]glycine, Nacalai Tesque, Inc.) and 50
mg (10.0 .mu.mol) of PEG-NCO (Shearwater Polymers, Inc., average
molecular weight: 5,000, structure:
CH.sub.3(OCH.sub.2CH.sub.2).sub.n--N.dbd.C.dbd.O) in a stream of
argon. To the solution were added 1.4 .mu.l (10.0 .mu.mol) of TEA
and then ca. 1 mg of copper chloride, followed by stirring at room
temperature for 5 hours. To the mixture were further added 10 mg of
PEG-NCO and 1 .mu.l of TEA, followed by stirring for 2 hours. Then,
15 mg of PEG-NCO was added and the mixture was stirred a whole day
and night at room temperature.
After addition of 50 ml of 0.1 mol/l hydrochloric acid, the mixture
was extracted with 50 ml of chloroform. The chloroform layer was
dried over anhydrous sodium sulfate and the solvent was removed
under reduced pressure. The residue was dissolved in a small amount
of methylene chloride and the solution was added dropwise to
diethyl ether. The formed white precipitate was recovered by
filtration to obtain 15 mg of a crude product containing the
desired compound (yield: 20%). This product was purified by DEAE
Sepharose F.F. column (Amersham-Pharmacia Biotech). Elution was
carried out with a 1 mol/l aqueous solution of sodium chloride, and
the eluate was extracted with chloroform under acidic conditions,
followed by drying over anhydrous sodium sulfate. Thereafter, the
solvent was removed under reduced pressure to obtain 6.0 mg of the
desired compound (yield: 8.0%).
<Gel Filtration HPLC Analysis>
The product was analyzed using TSKgelG2000SW.sub.XL column
(7.8.times.300 mm, Tosoh Corporation) under the following
conditions. Mobile phase: 150 mmol/l sodium chloride, 20 mmol/l
sodium acetate buffer (pH 4.5) Flow rate: 0.7 ml/minute Detection:
R.sup.1 Retention time: 11.5 minutes
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> .delta.
(ppm): 3.38(s, 9H), 3.64(s, 12nH), 4.10(s, 6H), 5.43(br, 3H)
EXAMPLE 2
Synthesis of 5 kDa Three-chain Branched Polyethylene
Glycol-shikimic Acid Derivative
Abbreviation: 5SKA(3UA)
In 250 .mu.l of DMF was dissolved 3.2 mg of shikimic acid, and 15
.mu.l of triethylamine and a catalytic amount of copper chloride
were added thereto. To the mixture was added 300 mg of PEG-NCO
(Shearwater Polymers, Inc., average molecular weight: 5,000,
structure: CH.sub.3(OCH.sub.2CH.sub.2).sub.n--N.dbd.C.dbd.O),
followed by stirring at room temperature for one hour. The reaction
mixture was added dropwise to diethyl ether, and the formed
precipitate was recovered by filtration and dried under reduced
pressure to obtain 270 mg (89%) of a crude desired product.
The product was purified using DEAE Sepharose F.F. column
(Amersham-Pharmacia Biotech) in a manner similar to that in Example
1. The desired fraction was extracted with chloroform and the
solvent was removed under reduced pressure to obtain 18 mg of the
desired compound (yield: 6%).
<Gel Filtration HPLC Analysis>
Measurement was carried out using TSKgelG2000SW.sub.XL column under
conditions similar to those in Example 1. Retention time: 11.7
minutes
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> .delta.(ppm):
3.38(s, 9H), 3.64(s, 12nH), 5.1-6.6(m, 4H)
EXAMPLE 3
Synthesis of 5 kDa Three- and Four-chain Branched Polyethylene
Glycol-quinic Acid Derivatives
Abbreviation: 5QNA(3UA), 5QNA(4UA)
In 250 .mu.l of DMF was dissolved 3 mg of quinic acid ((1R, 3R, 4R,
5R)-(-)-quinic acid), and 17 .mu.l of triethylamine and a catalytic
amount of copper chloride were added thereto. To the mixture was
added 344 mg of PEG-NCO (Shearwater Polymers, Inc.), followed by
stirring at room temperature for one hour. The reaction mixture was
added dropwise to diethyl ether, and the formed precipitate was
recovered by filtration and dried under reduced pressure to obtain
306 mg (88%) of a crude desired product. The product was purified
using DEAE Sepharose F.F. column (Amersham-Pharmacia Biotech) in a
manner similar to that in Example 1. The desired fraction was
extracted with chloroform, and the solvent was removed under
reduced pressure to obtain the following compounds.
TABLE-US-00003 TABLE 3 Retention Compound Number of Amount time in
gel abbrev. PEG bound of product Yield filtration HPLC* 5QNA (3UA)
3 24 mg 10.2% 11.7 minutes 5QNA (4UA) 4 17 mg 5.4% 11.1 minutes
*Measurement was carried out using TSKgelG2000SW.sub.XL column
under conditions similar to those in Example 1.
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> Compound
5QNA(3UA): .delta. (ppm): 3.38(s, 9H), 3.64(s, 12nH), 4.8-5.7(m,
3H)
Compound 5QNA(4UA): .delta. (ppm): 3.38(s, 12H), 3.64 (s, 16nH)
4.8-5.7(m, 3H)
EXAMPLE 4
Synthesis of 5 kDa Three-chain Branched Polyethylene
Glycol-pentaerythritol Derivative
Abbreviation: 5PET(3UA)
In 5 ml of DMF were dissolved 136 mg of pentaerythritol and 122 mg
of DMAP in a stream of argon, and 778 mg of CDI was added thereto.
The mixture was stirred a whole day and night at 0.degree. C. to
room temperature. In 10 ml of DMF was dissolved 5.0 g of
mPEG-NH.sub.2 (NOF Corporation, average molecular weight: 5,000,
structure: CH.sub.3(OCH.sub.2CH.sub.2).sub.n--CH.sub.2--NH.sub.2),
and 1.25 ml of the above reaction mixture was added thereto,
followed by stirring at room temperature for 2 hours. A solution of
2.6 g of .gamma.-aminobutyric acid in 100 ml of 0.1 mol/l borate
buffer (pH 10) was ice-cooled, and the reaction mixture was poured
into this solution. After stirring at 0.degree. C. for 2 hours and
at room temperature for 4 hours, the mixture was made acidic with
hydrochloric acid and then extracted with chloroform. The solvent
was removed under reduced pressure to obtain 4.2 g of a residue
(84.6%). The residue (3.8 g) was purified using DEAE Sepharose F.F.
column (1000 ml, Amersham-Pharmacia Biotech) in a manner similar to
that in Example 1 to obtain 254 mg of the desired compound (yield:
6.7%).
<Gel Filtration HPLC Analysis>
Measurement was carried out using TSKgelG2000SW.sub.XL column under
conditions similar to those in Example 1. Retention time: 11.4
minutes
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)>.delta. (ppm):
5.44(brt, J=5.0 Hz, 3H), 5.25(br, 1H), 4.09(brs, 8H), 3.65(s,
12nH), 3.29(s, 9H), 3.26(m, 8H), 2.37(t, J=6.8 Hz, 2H), 1.80(brm,
2H), 1.77(m, 6H)
EXAMPLE 5
Synthesis of 5 kDa Three-chain Branched Polyethylene
Glycol-pentaerythritol Derivative
Abbreviation: 5PET(3UM)
In 5 ml of DMF were dissolved 136 mg of pentaerythritol and 122 mg
of DMAP, and 778 mg of CDI was added thereto. The mixture was
stirred a whole day and night at 0.degree. C. to room temperature
in a stream of argon. In 2 ml of DMF was dissolved 1.0 g of
mPEG-NH.sub.2 (NOF Corporation, average molecular weight: 5,000),
and 0.25 ml of the above reaction mixture was added thereto,
followed by stirring at room temperature for 2 hours. Then, 187
.mu.l of propylenediamine was added thereto, and the mixture was
stirred at room temperature for 2 hours, followed by addition of
diethyl ether. The formed white precipitate was recovered and dried
under reduced pressure to obtain 975 mg of a residue (yield:
97.5%). The residue was purified using SP Sepharose F.F. column
(100 ml, Amersham-Pharmacia Biotech), and the fraction eluted with
0.2 to 0.4 mmol/l NaCl was extracted with chloroform to obtain 110
mg of a white powder (yield: 11.3%).
Subsequently, 100 mg of the white powder was dissolved in 0.5 ml of
a saturated aqueous solution of sodium hydrogencarbonate, and 2.3
mg of ethoxycarbonyl maleimide was added thereto at 0.degree. C.,
followed by stirring at 0.degree. C. for 10 minutes. After addition
of 1.5 ml of water, the mixture was stirred at room temperature for
15 minutes and then extracted with chloroform. The chloroform layer
was concentrated under reduced pressure and added dropwise to
diethyl ether. The formed white precipitate was dried under reduced
pressure to obtain 35 mg of the desired compound (yield: 35%).
<Gel Filtration HPLC Analysis>
Measurement was carried out using TSKgelG2000SW.sub.XL column under
conditions similar to those in Example 1. Retention time: 11.3
minutes
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> .delta.
(ppm): 6.73(s, 2H), 5.33(br, 3H), 4.08(brs, 8H), 3.64(s, 12nH),
3.36(s, 9H), 3.25(m, 6H), 3.11(m, 2H), 1.77(m, 8H)
EXAMPLE 6
Synthesis of Three-chain Branched Polyethylene
Glycol-pentaerythritol Derivative
Abbreviation: 5PET(3UU)
In 5 ml of DMF were dissolved 136 mg of pentaerythritol and 122 mg
of DMAP, and 681 mg of CDI was added thereto. The mixture was
stirred a whole day and night at 0.degree. C. to room temperature
in a stream of argon. In 2 ml of DMF was dissolved 1.0 g of
mPEG-NH.sub.2 (NOF Corporation, average molecular weight: 5,000),
and 286 .mu.l of the above reaction mixture was added thereto,
followed by stirring at room temperature for 2 hours. The resulting
reaction mixture was added dropwise to diethyl ether, and the
formed white precipitate was recovered and dried under reduced
pressure to obtain 1 g of a residue (yield: 100%).
The residue was purified using TSKgelODS-120T column (30
mm.times.250 mm, Tosoh Corporation). As an eluent, 0 to 90% aqueous
acetonitrile solution containing 0.1% TFA was used. The fraction
containing three-chain PEG was concentrated under reduced pressure
and extracted with chloroform, and the solvent was removed under
reduced pressure to obtain 165 mg of a residue (yield: 16.5%).
The obtained white powder (80 mg) was dissolved in 1 ml of
methylene chloride, and 4.1 mg of DSC and 2.1 mg of DMAP were added
thereto, followed by stirring at room temperature for 6 hours in a
stream of argon. The reaction mixture was added dropwise to diethyl
ether, and the formed white precipitate was dried under reduced
pressure to obtain 63 mg of the desired compound (yield:
78.8%).
<Gel Filtration HPLC Analysis>
Measurement was carried out using TSKgelG2000SW.sub.XL column under
conditions similar to those in Example 1. Retention time: 10.7
minutes
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> .delta.
(ppm): 5.49(br, 3H), 4.11(brs, 8H), 3.64(s, 12nH), 3.38(s, 9H),
3.25(m, 6H), 2.87(s, 4H), 1.78(m, 8H)
EXAMPLE 7
Synthesis of Three-chain Branched Polyethylene
Glycol-pentaerythritol Derivative
Abbreviation: 5PET(3URa)
In 5 ml of DMF were dissolved 136 mg of pentaerythritol and 122 mg
of DMAP, and 681 mg of CDI was added thereto. The mixture was
stirred a whole day and night at 0.degree. C. to room temperature
in a stream of argon. In 2 ml of DMF was dissolved 1.0 g of
mPEG-NH.sub.2 (NOF Corporation, average molecular weight: 5,000),
and 286 .mu.l of the above reaction mixture was added thereto,
followed by stirring at room temperature for 2 hours. The resulting
reaction mixture was added dropwise to diethyl ether, and the
formed white precipitate was recovered and dried under reduced
pressure to obtain 950 mg of a residue (yield: 95%). The residue
was purified using TSKgelODS-120T column (30 mm.times.250 mm, Tosoh
Corporation). As an eluent, 0 to 90% aqueous acetonitrile solution
containing 0.1% TFA was used. The fraction containing three-chain
PEG was concentrated under reduced pressure and extracted with
chloroform, and the solvent was removed under reduced pressure to
obtain 300 mg of a residue (yield: 31.6%).
The obtained residue (white powder, 300 mg) was dissolved in 1 ml
of methylene chloride, and 15.4 mg of DSC and 7.3 mg of DMAP were
added thereto, followed by stirring at room temperature for 6 hours
in a stream of argon. The reaction mixture was added dropwise to
diethyl ether, and the formed white precipitate was dried under
reduced pressure. The resulting dried product was dissolved in 1 ml
of methylene chloride, and 3.5 .mu.l of 4-aminobutyraldehyde
diethylacetal was added thereto, followed by stirring at room
temperature for 2 hours. The reaction mixture was added dropwise to
diethyl ether, and the formed white precipitate was dried under
reduced pressure to obtain 250 mg of a residue (yield: 83.3%).
The obtained residue (100 mg) was dissolved in methylene chloride
containing 10% TFA, and the solution was allowed to stand at
0.degree. C. for one hour. Then, the solution was added dropwise to
diethyl ether, and the formed white precipitate was dried under
reduced pressure to obtain 40 mg of the desired compound (yield:
40.0%).
<Gel Filtration HPLC Analysis>
Measurement was carried out using TSKgelG2000SW.sub.XL column under
conditions similar to those in Example 1. Retention time: 10.6
minutes
EXAMPLE 8
Synthesis of Three- and Four-chain Branched Polyethylene
Glycol-carbohydrate Derivatives
Abbreviation: 5SUG(3UA), 5SUG(4UA)
In 80 ml of DMF was dissolved 5.18 g of .alpha.-D-glucose
pentaacetate, and 2.37 g of hydrazine acetate was added thereto,
followed by stirring at room temperature for 1.5 hours. The
reaction mixture was extracted with ethyl acetate, and the ethyl
acetate layer was washed with water and a saturated aqueous
solution of sodium chloride, and then dried over anhydrous sodium
sulfate. The solution was concentrated under reduced pressure to
obtain 4.0 g of .alpha.-D-glucopyranose-2,3,4,6-tetraacetate
(yield: 87%).
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> .delta.
(ppm): 2.02(s, 3H), 2.03(s, 3H), 2.08(s, 3H), 2.10(s, 3H), 4.14(m,
1H), 4.27(m, 2H), 4.91(m, 1H), 5.09(t, J=9.7 Hz, 1H), 5.47(d, J=3.7
Hz, 1H), 5.55(t, J=9.8 Hz, 1H)
The above compound (850 mg) was dissolved in 15 ml of methylene
chloride, and 4.8 ml of trichloroacetonitrile and 365 ml of DBU
(1,8-diazabicyclo[5.4.0]undec-7-ene) were added thereto at
0.degree. C., followed by stirring at 0.degree. C. for one hour and
at room temperature for 15 minutes. The resulting solution was
concentrated under reduced pressure and then purified using a
silica gel column to obtain 635 mg of
.alpha.-D-glucopyranose-2,3,4,6-tetraacetate-1-(2,2,2-trichloroethanimida-
te) (yield: 53%).
<.sup.1H-NMR analysis (CDCl.sub.3, 300 MHz)> .delta. (ppm):
2.02(s, 3H), 2.04(s, 3H), 2.06(s, 3H), 2.08(s, 3H), 4.13(m, 1H),
4.21(m, 1H), 4.28(m, 1H), 5.13(m, 1H), 5.19(t, J=9.8 Hz, 1H),
5.57(t, J=9.9 Hz, 1H), 6.56(d, J=3.7 Hz, 1H), 8.71(s, 1H)
The above compound (693 mg) and 109 .mu.l of methyl glycolate were
dissolved in dehydrated methylene chloride, and 1.62 g of molecular
sieves 4A was added thereto, followed by stirring at room
temperature for 4 hours in a stream of argon. The reaction mixture
was cooled to 0 to 5.degree. C., and 163 .mu.l of a mixed solution
of trimethylsilyl trifluoromethanesulfonate and dehydrated
methylene chloride (2:1) was added thereto, followed by stirring at
0 to 5.degree. C. for 19 hours. After addition of 77 .mu.l of
triethylamine, the mixture was filtered through Celite. The
resulting solution was concentrated under reduced pressure and then
purified using a silica gel column to obtain 162 mg of
[(2,3,4,6-tetra-O-acetyl-.beta.-D-glucopyranosyl)oxy] acetic acid
methyl ester (yield: 27%).
<.sup.1H-NMR analysis (CDCl.sub.3, 300 MHz)> .delta. (ppm):
2.01(s, 3H), 2.03(s, 3H), 2.09(s, 3H), 2.10(s, 3H), 3.70(m, 1H),
3.75(s, 3H), 4.14(m, 1H), 4.26(m, 1H), 4.29(s, 2H), 4.67(d, J=7.8
Hz, 1H), 5.05(m, 1H), 5.09(t, J=10.8 Hz, 1H), 5.25(t, J=9.5 Hz,
1H)
The above compound (162 mg) was dissolved in 1 ml of methanol, and
Amberlyst was added thereto. Then, 9.4 .mu.l of a 28% solution of
sodium methoxide in methanol was added, and the mixture was stirred
at room temperature for 3 hours. After filtration through Celite,
the filtrate was concentrated under reduced pressure to obtain 80
mg of [(.beta.-D-glucopyranosyl)oxy] acetic acid methyl ester
(yield: 82%).
<.sup.1H-NMR analysis (D.sub.2O, 300 MHz)> .delta. (ppm):
3.39(s, 2H), 3.40(m, 2H), 3.69(m, 1H), 3.75(s, 3H), 3.86(m, 1H),
4.06(m, 1H), 4.26(m, 1H), 4.44(m, 1H) <Mass spectrum
(FAB-MS)> Found: [M+H]=253 Calcd.:
C.sub.9H.sub.16O.sub.8=252
The above compound (2 mg) was dissolved in 100 .mu.l of DMF, and 7
.mu.l of triethylamine and a catalytic amount of CuCl were added
thereto. To the mixture was added 160 mg of mPEG-NCO, and the
mixture was stirred at room temperature for 2 hours. Then, 80 mg of
mPEG-NCO was added, followed by further stirring for 3 hours. The
resulting solution was added dropwise to diethyl ether, and the
formed white precipitate was recovered by filtration and dried
under reduced pressure. The obtained white solid (200 mg) was
dissolved in 2 ml of 1 mol/l aqueous solution of potassium
carbonate, followed by stirring at room temperature for 4 hours. To
the solution were added chloroform and 0.1 mol/l hydrochloric acid,
and the mixture was extracted with chloroform. After the extract
was dried over anhydrous sodium sulfate, the solvent was removed
under reduced pressure, and the residue was dried under reduced
pressure to obtain 195 mg of a white solid. This product was
purified using DEAE Sepharose F.F. column (20 ml,
Amersham-Pharmacia Biotech) to obtain the compounds shown
below.
TABLE-US-00004 TABLE 4 Compound Number of Amount of Retention time
in gel abbrev. PEG bound product Yield filtration HPLC* 5SUG (3UA)
3 6 mg 5.0% 10.8 minutes 5SUG (4UA) 4 12 mg 7.6% 10.4 minutes
*Measurement was carried out using TSKgelG2000SW.sub.XL column
under conditions similar to those in Example 1.
<.sup.1H-NMR analysis (300 MHz, in CDCl.sub.3)> Compound
5SUG(3UA): .delta. (ppm): 3.38 (s, 9H), 3.64(t, 12nH) 4.1-5.6(m,
7H) Compound 5SUG(4UA): .delta. (ppm): 3.38(s, 12H), 3.64(t, 16nH),
4.1-5.6(m, 7H)
EXAMPLE 9
Preparation of Recombinant Human Interferon-.beta. Modified with 5
KDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5TRC(3UA)-rhIFN-.beta.
To 5 mg (0.33 .mu.mol) of the compound of Example 1 (5TRC(3UA))
were added 50 .mu.l (0.66 .mu.mol) of 1.5 mg/ml solution of NHS in
methylene chloride and 100 .mu.l (0.66.mu.mol) of 1.4 mg/ml
solution of DCC in methylene chloride, followed by stirring in a
stream of argon under ice-cooling for 30 minutes and at room
temperature for 2 hours. After addition of diethyl ether, the
formed precipitate was dried under reduced pressure to obtain 3.5
mg (yield: 70%) of NHS ester.
To 150 .mu.l of a 0.9 mg/ml solution of rhIFN-.beta. obtained in
Reference Example 4 in 20 mmol/l phosphate buffer containing
ethylene glycol and sodium chloride was added 33.4 mg (34 mol per
mol of protein) of the modifying reagent activated above (NHS
ester), and the mixture was subjected to reaction by standing a
whole day and night at 4.degree. C. The reaction mixture was
applied to a gel filtration column Sephadex G-25
(Amersham-Pharmacia Biotech) and subjected to buffer exchange with
20 mmol/l phosphate buffer (pH 6.0) containing ethylene glycol,
followed by purification using CM Sepharose F.F. column (0.5 ml,
Amersham-Pharmacia Biotech). After the reaction mixture was
charged, the column was washed with 5 ml of the same buffer, and
elution was carried out with the buffer containing sodium chloride.
The fraction containing the desired substance was recovered to
obtain 0.40 ml of the desired substance (0.091 mg/ml) (yield:
27.0%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol under
the following conditions to confirm the bands of 1 to 3
molecules-bound substances. Gel: PAGEL SPG 520L (Atto Corporation)
Staining: FAST STAIN.TM. Molecular weight marker: Low Molecular
Weight Standard (Bio-Rad) <Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns
under the following conditions. Mobile phase: 150 mmol/l sodium
chloride, 20 mmol/l sodium acetate buffer (pH 4.5) Flow rate: 0.5
ml/minute Detection: UV 280 nm Separation column:
TSKgelG4000SW.sub.XL (7.8.times.300 mm.times.2, Tosoh Corporation)
Retention time: 42.0 minutes (1 molecule-bound substance) 44.1
minutes (2 molecules-bound substance)
EXAMPLE 10
Preparation of Recombinant Human Interferon-.beta. Modified with 5
kDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5SKA(3UA)-rhIFN-.beta.
In 100 .mu.l of methylene chloride was dissolved 16 mg (1.1
.mu.mol) of the compound of Example 2 (5SKA(3UA)), and 272 .mu.g of
DCC and 152 .mu.g of NHS were added thereto, followed by stirring
under ice-cooling for one hour and at room temperature for one
hour. The mixture was added dropwise to diethyl ether, and the
formed white precipitate was dried under reduced pressure to obtain
14.5 mg of NHS ester of the compound of Example 2 (yield: 91%).
To 100 .mu.l of a 1.2 mg/ml solution of rhIFN-.beta. obtained in
Reference Example 4 in 20 mmol/l phosphate buffer containing
ethylene glycol and sodium chloride was added 8.6 mg (100 mol per
mol of protein) of the NHS ester obtained above, and the mixture
was subjected to reaction by standing a whole day and night at
4.degree. C. The reaction mixture was applied to a gel filtration
column Sephadex G-25 (Amersham-Pharmacia Biotech) and subjected to
buffer exchange with 20 mmol/l phosphate buffer (pH 6.0) containing
ethylene glycol, followed by purification using CM Sepharose F.F.
column (0.6 ml, Amersham-Pharmacia Biotech). After the reaction
mixture was charged, the column was washed with 3 ml of the same
buffer, and elution was carried out with the buffer containing
sodium chloride. The fraction containing the desired substance was
recovered to obtain 80 .mu.l of the desired substance (47 .mu.g/ml)
(yield: 3.3%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the band of 1 molecule-bound
substance.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 41.7 minutes (1
molecule-bound substance)
EXAMPLE 11
Preparation of Recombinant Human Interferon-.beta. Modified with 5
kDa Three-Chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UU)-rhIFN-.beta.
To 0.5 ml of a 1.2 mg/ml solution of rhIFN-.beta. obtained in
Reference Example 4 in 20 mmol/l phosphate buffer (pH 7.8)
containing ethylene glycol and sodium chloride was added 4.5 mg (10
mol per mol of protein) of 5PET(3UU) obtained in Example 6, and the
mixture was subjected to reaction a whole day and night at
4.degree. C. The reaction mixture (0.5 ml) was applied to Sephadex
G-25 column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l phosphate buffer (pH 6) containing ethylene
glycol. The mixture was passed through CM-Sepharose F.F. column
(0.8 ml, Amersham-Pharmacia Biotech), followed by washing with 4.0
ml of 20 mmol/l phosphate buffer (pH 6) containing ethylene glycol.
Elution was carried out with the same buffer containing 0.1 to 0.5
mol/l sodium chloride, and the desired fractions were combined and
then concentrated to obtain 0.36 ml of a solution containing the
desired substance (0.67 mg/ml) (yield: 40%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 41.1 minutes (1
molecule-bound substance) 38.2 minutes (2 molecules-bound
substance)
EXAMPLE 12
Preparation of Recombinant Human Interferon-.beta. Modified with 5
kDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UA)-rhIFN-.beta.
In 2.0 ml of methylene chloride was dissolved 254 mg (0.02 mmol) of
the compound of Example 4 (5PET(3UA)), and 5.9 mg (0.05 mmol) of
NHS and 10.5 mg (0.05 mmol) of DCC were added thereto, followed by
stirring in a stream of argon at 0.degree. C. for one hour and at
room temperature for 2 hours. The reaction mixture was added
dropwise to diethyl ether, and the formed white precipitate was
dried under reduced pressure to obtain 132.8 mg of NHS ester of the
compound of Example 4 (yield: 52.3%).
To 1.0 ml of a 1.16 mg/ml solution of rhIFN-.beta. obtained in
Reference Example 4 in 20 mmol/l phosphate buffer (pH 7.8)
containing ethylene glycol and sodium chloride was added 13 mg (15
mol per mol of protein) of the above NHS ester of 5PET(3UA), and
the mixture was subjected to reaction a whole day and night at
4.degree. C. The reaction mixture was applied to Sephadex G-25
column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l phosphate buffer (pH 6) containing ethylene
glycol. The mixture was passed through CM-Sepharose F.F. column
(1.4 ml, Amersham-Pharmacia Biotech), followed by washing with 7.0
ml of 20 mmol/l phosphate buffer (pH 6) containing ethylene glycol.
Elution was carried out with the same buffer containing 0.1 to 0.5
mol/l sodium chloride, and the desired fractions were combined and
then concentrated to obtain 1.0 ml of a solution containing the
desired substance (0.14 mg/ml) (yield: 12%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 43.8 minutes (1
molecule-bound substance) 41.2 minutes (2 molecules-bound
substance)
EXAMPLE 13
Preparation of Recombinant Human Interferon-.beta. Modified with 5
kDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UA)-.sup.17Ser rhIFN-.beta.
To 0.05 ml of a 2.1 mg/ml solution of .sup.17Ser rhIFN-.beta.
(Chiron) in 20 mmol/l phosphate buffer (pH 7.5) containing ethylene
glycol and sodium chloride was added 1.6 mg (20 mol per mol of
protein) of NHS ester of 5PET(3UA) obtained in a manner similar to
Example 12, and the mixture was subjected to reaction a whole day
and night at 4.degree. C. The reaction mixture was applied to
Sephadex G-25 column (Amersham-Pharmacia Biotech) and subjected to
buffer exchange with 20 mmol/l phosphate buffer (pH 6) containing
ethylene glycol. The fraction obtained by gel filtration was passed
through CM-Sepharose F.F. column (0.5 ml, Amersham-Pharmacia
Biotech), followed by washing with 8 ml of 20 mmol/l phosphate
buffer (pH 6) containing ethylene glycol. Elution was carried out
with the same buffer containing 0.2 to 1.0 mol/l sodium chloride,
and the desired fractions were combined and then concentrated to
obtain 0.30 ml of a solution containing the desired substance (27.8
.mu.g/ml) (yield: 7.9%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
EXAMPLE 14
Preparation of Recombinant Human Interferon-.alpha. Modified with 5
kDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UA)-rhIFN-.alpha.
To 0.1 ml of a 1.0 mg/ml solution of rhIFN-.alpha. (IBL Co., Ltd.)
in isotonic phosphate buffer (pH 7.5) was added 1.6 mg (20 mol per
mol of protein) of NHS ester of 5PET(3UA) obtained in a manner
similar to Example 12, and the mixture was subjected to reaction a
whole day and night at 4.degree. C. The reaction mixture was
applied to Sephadex G-25 column (Amersham-Pharmacia Biotech) and
subjected to buffer exchange with 20 mmol/l sodium acetate buffer
(pH 4.5). The mixture was passed through SP-Sepharose F.F. column
(0.7 ml, Amersham-Pharmacia Biotech), followed by washing with 20
mmol/l sodium acetate buffer (pH 4.5). Elution was carried out with
the same buffer containing 0.1 to 0.5 mol/l sodium chloride, and
the desired fractions were combined and then concentrated to obtain
65 .mu.l of a solution containing the desired substance (0.53
mg/ml) (yield: 34%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 42.6 minutes (1
molecule-bound substance) 40.3 minutes (2 molecules-bound
substance)
EXAMPLE 15
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 KDa Three-chain Branched
Polyethylene Glycol
Abbreviation: 5SKA(3UA)-rhG-CSF derivative
In 100 .mu.l of methylene chloride was dissolved 16 mg (1.1
.mu.mol) of the compound of Example 2 (5SKA(3UA)), and 272 .mu.g of
DCC and 152 .mu.g of NHS were added thereto, followed by stirring
under ice-cooling for one hour and at room temperature for one
hour. The reaction mixture was added dropwise to diethyl ether, and
the formed white precipitate was dried under reduced pressure to
obtain 14.5 mg of NHS ester of the compound of Example 2 (yield:
91%).
To 50 .mu.l of a 3.7 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 50 mmol/l phosphate buffer (pH
7.5) was added 3.6 mg (25 mol per mol of protein) of the compound
activated above (NHS ester), and the mixture was subjected to
reaction a whole day and night at 4.degree. C. The reaction mixture
was applied to Sephadex G-25 column (Amersham-Pharmacia Biotech)
and subjected to buffer exchange with 20 mmol/l acetate buffer (pH
4.5), followed by purification using SP Sepharose F.F. column (0.7
ml, Amersham-Pharmacia Biotech). The desired fraction was
concentrated to obtain 165 .mu.l of a solution containing the
desired substance (0.4 mg/ml) (yield: 36%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 42.3 minutes (1
molecule-bound substance) 40.2 minutes (2 molecules-bound
substance)
EXAMPLE 16
Preparation of a Solution Containing Recombinant Human
Granulocyte-colony Stimulating Factor Modified with 5 KDa
Four-chain Branched Polyethylene Glycol
Abbreviation: 5QNA(4UA)-rhG-CSF derivative
In 500 .mu.l of methylene chloride was dissolved 69 mg (3.5 mmol)
of the compound of Example 3 (5QNA(4UA)), and 1.8 mg of DSC and
0.56 mg of DMAP were added thereto, followed by stirring at room
temperature for 6 hours. The reaction mixture was added dropwise to
diethyl ether, and the formed white precipitate was dried under
reduced pressure to obtain 44 mg of NHS ester of the compound of
Example 3 (yield: 63%).
To 50 .mu.l of a 3.8 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 50 mmol/l phosphate buffer (pH
8) was added 5.1 mg (25 mol per mol of protein) of the compound
activated above (NHS ester), and the mixture was subjected to
reaction a whole day and night at 4.degree. C. Without further
purification steps, the resulting product was confirmed by
electrophoresis and gel filtration HPLC analysis.
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the band of 1 molecule-bound
substance.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 40.8 minutes (1
molecule-bound substance)
EXAMPLE 17
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Modified with 5 KDa Three-chain Branched Polyethylene
Glycol
Abbreviation: 5SKA(3UA)-rhG-CSF
In 100 .mu.l of methylene chloride was dissolved 16 mg (1.1
.mu.mol) of the compound of Example 2 (5SKA(3UA)), and 272 .mu.g of
DCC and 152 .mu.g of NHS were added thereto, followed by stirring
under ice-cooling for one hour and at room temperature for one
hour. The reaction mixture was added dropwise to diethyl ether, and
the formed white precipitate was dried under reduced pressure to
obtain 14.5 mg of NHS ester of the compound of Example 2 (yield:
91%).
To 140 .mu.l of a 4.4 mg/ml solution of the rhG-CSF obtained in
Reference Example 6 in 50 mmol/l phosphate buffer (pH 7.5) was
added 12.2 mg (25 mol per mol of protein) of the compound activated
above (NHS ester), and the mixture was subjected to reaction a
whole day and night at 4.degree. C. The reaction mixture was
applied to Sephadex G-25 column (Amersham-Pharmacia Biotech) and
subjected to buffer exchange with 20 mmol/l acetate buffer (pH
4.5), followed by purification using SP Sepharose F.F. column (1.8
ml, Amersham-Pharmacia Biotech). The desired fraction was
concentrated to obtain 110 .mu.l of a solution containing the
desired substance (1.1 mg/ml) (yield: 19%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 40 to 45 minutes (1
to 3 molecules-bound substances)
EXAMPLE 18
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 KDa Three-chain Branched
Polyethylene Glycol
Abbreviation: 5PET(3UU)-rhG-CSF derivative
To 0.5 ml of a 3.1 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 20 mmol/l phosphate buffer (pH
7.5) was added 12.2 mg (10 mol per mol of protein) of 5PET(3UU)
obtained in Example 6, and the mixture was subjected to reaction a
whole day and night at 4.degree. C. The reaction mixture was
applied to Sephadex G-25 column (Amersham-Pharmacia Biotech) and
subjected to buffer exchange with 20 mmol/l sodium acetate buffer
(pH 4.5). The mixture was passed through SP-Sepharose F.F. column
(1.5 ml, Amersham-Pharmacia Biotech), followed by washing with 7.5
ml of 20 mmol/l sodium acetate buffer (pH 4.5). Elution was carried
out with the same buffer containing 0.2 to 0.5 mol/l sodium
chloride, and the desired fractions were combined and then
concentrated to obtain 0.75 ml of a solution containing the desired
substance (1.2 mg/ml) (yield: 58.6%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 40.5 minutes (1
molecule-bound substance) 37.8 minutes (2 molecules-bound
substance)
EXAMPLE 19
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 KDa Three-chain Branched
Polyethylene Glycol
Abbreviation: 5PET(3UA)-rhG-CSF Derivative
To 0.05 ml of a 4.0 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 20 mmol/l phosphate buffer (pH
7.5) was added 1.6 mg (10 mol per mol of protein) of NHS ester of
5PET(3UA) obtained in a manner similar to Example 12, and the
mixture was subjected to reaction a whole day and night at
4.degree. C. The reaction mixture was applied to Sephadex G-25
column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l sodium acetate buffer (pH 4.5). The mixture
was passed through SP-Sepharose F.F. column (0.7 ml,
Amersham-Pharmacia Biotech), followed by washing with 20 mmol/l
sodium acetate buffer (pH 4.5). Elution was carried out with the
same buffer containing 0.2 to 0.5 mol/l sodium chloride, and the
desired fractions were combined and then concentrated to obtain
0.30 ml of a solution containing the desired substance (0.34 mg/ml)
(yield: 56.7%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 42.3 minutes (1
molecule-bound substance) 39.5 minutes (2 molecules-bound
substance)
EXAMPLE 20
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 kDa Three-chain Branched
Polyethylene Glycol
Abbreviation: 5SUG(3UA)-rhG-CSF Derivative
To 100 mg (6.7 .mu.mol) of the compound obtained in Example 8
(5SUG(3UA)) were added 2.3 mg of NHS and 4.1 mg of DCC, and the
mixture was dissolved in 1 ml of methylene chloride under
ice-cooling, followed by stirring under ice-cooling for one hour
and at room temperature for 1.5 hours. The reaction mixture was
added dropwise to diethyl ether and the formed white precipitate
was dried under reduced pressure to obtain 76.6 mg of NHS ester of
the compound of Example 8 (yield: 76.6%).
To 0.1 ml of a 3.9 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 50 mmol/l phosphate buffer (pH
7.5) was added 10.7 mg (35 mol per mol of protein) of the compound
activated above (NHS ester), and the mixture was subjected to
reaction a whole day and night at 4.degree. C. The reaction mixture
was applied to Sephadex G-25 column (Amersham-Pharmacia Biotech)
and subjected to buffer exchange with 20 mmol/l sodium acetate
buffer (pH 4.5). The mixture was passed through SP-Sepharose F.F.
column (0.7 ml, Amersham-Pharmacia Biotech), followed by washing
with 20 mmol/l sodium acetate buffer (pH 4.5). Elution was carried
out with the same buffer containing 0.2 to 0.5 mol/l sodium
chloride, and the desired fractions were combined and then
concentrated to obtain 0.39 ml of a solution containing the desired
substance (0.28 mg/ml) (yield: 27.8%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 43.0 minutes (1
molecule-bound substance) 40.4 minutes (2 molecules-bound
substance)
EXAMPLE 21
Preparation of Human Cu, Zn-superoxide Dismutase Modified with 5
kDa Three-chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UM)-hSOD
To 0.5 ml of a 1.34 mg/ml solution of Cu, Zn-hSOD (CELLULAR
PRODUCTS, INC.) in 50 mmol/l phosphate buffer (pH 7.5) was added
3.1 mg (10 mol per mol of protein) of 5PET(3UM) obtained in Example
5, and the mixture was subjected to reaction a whole day and night
at 4.degree. C. The reaction mixture was applied to Sephadex G-25
column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l sodium acetate buffer (pH 3.5). The mixture
was passed through SP-Sepharose F.F. column (0.7 ml,
Amersham-Pharmacia Biotech), followed by washing with 20 mmol/l
sodium acetate buffer (pH 3.5). Elution was carried out with the
same buffer containing 0.5 to 1.0 mol/l sodium chloride, and the
desired fractions were combined and then concentrated to obtain
0.62 ml of a solution containing the desired substance (0.33 mg/ml)
(yield: 30.6%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the band of 1 molecule-bound
substance.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 41.1 minutes (1
molecule-bound substance)
EXAMPLE 22
Preparation of Anti-GD3 Chimera Antibody Modified with 5 kDa
Three-chain Branched Polyethylene Glycol
Abbreviation: 5PET(3UA)-KM871
To 1.0 ml of a 1.1 mg/ml solution of anti-GD3 chimera antibody
(KM-871) in 20 mmol/l phosphate buffer (pH 7.5) (prepared according
to Japanese Published Unexamined Patent Application No. 304989/93)
was added 0.6 mg (5 mol per mol of protein) of NHS ester of
5PET(3UA) obtained in a manner similar to Example 12, and the
mixture was subjected to reaction a whole day and night at
4.degree. C. The reaction mixture (1.0 ml) was applied to Sephadex
G-25 column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l acetate buffer (pH 4.5). The mixture was
passed through CM-Sepharose F.F. column (1.0 ml, Amersham-Pharmacia
Biotech), followed by washing with 20 mmol/l sodium acetate buffer
(pH 4.5). Elution was carried out with the same buffer containing
0.25 to 1.0 mol/l sodium chloride, and the desired fractions were
combined and then concentrated to obtain 430 .mu.l of a solution
containing the desired substance (0.52 mg/ml) (yield: 20.4%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 2
molecules-bound substances.
EXAMPLE 23
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 KDa Three-chain Branched
Polyethylene Glycol
Abbreviation: 5PET(3URa)-rhG-CSF Derivative
To 0.6 ml of a 2.35 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 50 mmol/l phosphate buffer (pH
7.5) were added 56.3 mg (50 mol per mol of protein) of the compound
of Example 7 (5PET(3URa)) and 10 .mu.l of a 120 mmol/l aqueous
NaBH.sub.3CN solution. The mixture was subjected to reaction a
whole day and night at 4.degree. C. and then made acidic with
hydrochloric acid to stop the reaction. The reaction mixture was
applied to Sephadex G-25 column (Amersham-Pharmacia Biotech) and
subjected to buffer exchange with 20 mmol/l sodium acetate buffer
(pH 4.5). The mixture was passed through SP-Sepharose F.F. column
(1.4 ml, Amersham-Pharmacia Biotech), followed by washing with 20
mmol/l sodium acetate buffer (pH 4.5). Elution was carried out with
the same buffer containing 0.1 to 0.2 mol/l sodium chloride, and
the desired fractions were combined and then concentrated to obtain
0.55 ml of a solution containing the desired substance (0.24 mg/ml)
(yield: 8.5%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the band of 1 molecule-bound
substance.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 41.2 minutes (1
molecule-bound substance)
REFERENCE EXAMPLE 1
Preparation of Recombinant Human Interferon-.beta. Modified with 5
kDa Double-chain Branched Polyethylene Glycol (A Conventional
Reagent)
Abbreviation: PEG.sub.2Lys-rhIFN-.beta.
To 1.3 ml of a 0.97 mg/ml solution of rhIFN-.beta. obtained in
Reference Example 4 in 20 mmol/l phosphate buffer (pH 7.8)
containing ethylene glycol and sodium chloride was added 8.3 mg
(12.5 mol per mol of protein) of PEG.sub.2Lys (average molecular
weight: 10,000, Shearwater Polymers, Inc.), and the mixture was
subjected to reaction a whole day and night at 4.degree. C. The
reaction mixture was applied to Sephadex G-25 column
(Amersham-Pharmacia Biotech) and subjected to buffer exchange with
20 mmol/l sodium acetate buffer (pH 6) containing ethylene glycol.
The mixture was passed through CM-Sepharose F.F. column (1.4 ml,
Amersham-Pharmacia Biotech), followed by washing with 20 mmol/l
sodium acetate buffer (pH 6) containing ethylene glycol. Elution
was carried out with the same buffer containing 0.1 to 0.5 mol/l
sodium chloride, and the desired fractions were combined and then
concentrated to obtain 2.7 ml of a solution containing the desired
substance (0.36 mg/ml) (yield: 76.7%).
<Electrophoresis>
SDS-PAGE was carried out in the presence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 45.3 minutes (1
molecule-bound substance) 41.5 minutes (2 molecules-bound
substance)
REFERENCE EXAMPLE 2
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative Modified with 5 KDa Double-chain Branched
Polyethylene Glycol (a Conventional Reagent)
Abbreviation: PEG.sub.2Lys-rhG-CSF derivative
To 0.5 ml of a 4.0 mg/ml solution of the rhG-CSF derivative
obtained in Reference Example 5 in 50 mmol/l phosphate buffer (pH
7.5) was added 10.6 mg (10 mol per mol of protein) of PEG.sub.2Lys
(average molecular weight: 10,000, Shearwater Polymers, Inc.), and
the mixture was subjected to reaction a whole day and night at
4.degree. C. The reaction mixture was applied to Sephadex G-25
column (Amersham-Pharmacia Biotech) and subjected to buffer
exchange with 20 mmol/l sodium acetate buffer (pH 4.5). The mixture
was passed through SP-Sepharose F.F. column (2.0 ml,
Amersham-Pharmacia Biotech), followed by washing with 10 ml of 20
mmol/l sodium acetate buffer (pH 4.5). Elution was carried out with
the same buffer containing 0.2 to 0.5 mol/l sodium chloride, and
the desired fractions were combined and then concentrated to obtain
0.5 ml of a solution containing the desired substance (1.05 mg/ml)
(yield: 26.3%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 44.3 minutes (1
molecule-bound substance) 41.7 minutes (2 molecules-bound
substance)
REFERENCE EXAMPLE 3
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Modified with 5 KDa Single-chain Polyethylene Glycol (a
Conventional Reagent)
Abbreviation: PEG.sub.2Lys-rhG-CSF
To 0.5 ml of a 4.4 mg/ml solution of rhG-CSF obtained in Reference
Example 6 in isotonic phosphate buffer (pH 7.4) was added 11.7 mg
(10 mol per mol of protein) of PEG.sub.2Lys (average molecular
weight: 10,000, Shearwater Polymers, Inc.), and the mixture was
subjected to reaction a whole day and night at 4.degree. C. The
reaction mixture was applied to Sephadex G-25 column
(Amersham-Pharmacia Biotech) and subjected to buffer exchange with
20 mmol/l acetate buffer (pH 4.5). The mixture was passed through
SP-Sepharose F.F. column (2.0 ml, Amersham-Pharmacia Biotech),
followed by washing with 10 ml of 20 mmol/l sodium acetate buffer
(pH 4.5). Elution was carried out with the same buffer containing
0.2 to 0.5 mol/l sodium chloride, and the desired fractions were
combined and then concentrated to obtain 0.5 ml of a solution
containing the desired substance (1.78 mg/ml) (yield: 40.5%).
<Electrophoresis>
SDS-PAGE was carried out in the absence of 2-mercaptoethanol in a
manner similar to Example 9 to confirm the bands of 1 to 3
molecules-bound substances.
<Gel Filtration HPLC Analysis>
Analysis was carried out using two TSKgelG4000SW.sub.XL columns in
a manner similar to Example 9. Retention time: 44.2 minutes (1
molecule-bound substance) 41.8 minutes (2 molecules-bound
substance)
REFERENCE EXAMPLE 4
Preparation of Recombinant Human Interferon-.beta. (Unmodified
rhIFN-.beta.)
rhIFN-.beta. having the amino acid sequence shown in SEQ ID NO: 1
was produced according to the method of Mizukami, et al.
[Biotechnology Letter, Vol. 8, p. 605 (1986)] and the method of
Kuga, et al. [Chemistry Today, extra number 12: Gene Engineering in
Medical Science, p. 135 (1986), Tokyo Kagaku Dojin].
Escherichia coli K-12 carrying plasmid pMG-1 comprising DNA
encoding rhIFN-.beta. was seed-cultured in LGTrpAp medium (10 g/l
bactotrypton, 5 g/l yeast extract, 5 g/l sodium chloride, 1 g/l
glucose, 50 mg/l L-tryptophan and 50 .mu.g/l ampicillin). For the
production of rhIFN-.beta., culturing was carried out in a 2-l jar
fermenter using MCGAp medium (a medium prepared by adding 0.5%
Casamino acid and 50 .mu.g/ml ampicillin to M9 medium) at
20.degree. C. for several days, during which the glucose
concentration was maintained at 1% and pH at 6.5. The culture was
shaken at 750 rpm and aerated at 1 l/minute. From the culture, an
extract was prepared by the freezing and thawing method [DNA, Vol.
2, p. 265 (1983)]. Further, rhIFN-.beta. was obtained from the cell
residue according to the method disclosed in Japanese Published
Unexamined Patent Application No. 69799/86.
REFERENCE EXAMPLE 5
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor Derivative (Unmodified rhG-CSF Derivative)
An rhG-CSF derivative wherein threonine at position 1 was replaced
with alanine, leucine at position 3 was replaced with threonine,
glycine at position 4 was replaced with tyrosine, proline at
position 5 was replaced with arginine and cysteine at position 17
was replaced with serine in hG-CSF having the amino acid sequence
shown in SEQ ID NO: 2 was obtained by the method described in
Japanese Published Examined Patent Application No. 96558/95.
Escherichia coli W3110strA carrying plasmid pCfBD28 comprising DNA
encoding the above rhG-CSF derivative (Escherihica coli ECfBD28
FERM BP-1479) was cultured in LG medium (a medium prepared by
dissolving 10 g of bactotrypton, 5 g of yeast extract, 5 g of
sodium chloride and 1 g of glucose in 1 L of water and adjusted to
pH 7.0 with NaOH) at 37.degree. C. for 18 hours. The resulting
culture (5 ml) was inoculated into 100 ml of MCG medium (0.6%
Na.sub.2HPO.sub.4, 0.3% KH.sub.2PO.sub.4, 0.5% sodium chloride,
0.5% Casamino acid, 1 mmol/l MgSO.sub.4, 14 .mu.g/ml vitamin B, pH
7.2) containing 25 .mu.g/ml tryptophan and 50 .mu.g/ml ampicillin.
After culturing at 30.degree. C. for 4 to 8 hours, 10 .mu.g/ml
3.beta.-indoleacrylic acid (hereinafter abbreviated as IAA), a
tryptophan inducer, was added, followed by further culturing for 2
to 12 hours. The obtained culture was centrifuged at 8,000 rpm for
10 minutes to collect cells, and the cells were washed with a 30
mmol/l aqueous solution of sodium chloride and 30 mmol/l
tris-hydrochloride buffer (pH 7.5). The washed cells were suspended
in 30 ml of the above buffer and disrupted by ultrasonication
(BRANSON SONIC POWER COMPANY, SONIFIER CELL DISRUPTOR 200, OUTPUT
CONTROL 2) at 0.degree. C. for 10 minutes. The ultrasonicated cells
were centrifuged at 9,000 rpm for 30 minutes to obtain cell
residue.
From the cell residue, the rhG-CSF derivative was extracted,
purified, solubilized and regenerated in accordance with the method
of Marston, et al. [BIO/TECHNOLOGY, Vol. 2, p. 800 (1984)].
REFERENCE EXAMPLE 6
Preparation of Recombinant Human Granulocyte-colony Stimulating
Factor (Unmodified rhG-CSF)
rhG-CSF having the amino acid sequence shown in SEQ ID NO: 2 was
prepared according to the method described in Reference Example
5.
TEST EXAMPLE 1
Antiviral Activity of Chemically Modified Interferon-.beta.
The antiviral activity of the chemically modified rhIFN-.beta.
obtained in Examples 9, 10, 12 and 13 and unmodified rhIFN-.beta.
was examined by the following neutral red (NR) uptake method.
<NR Uptake Method>
The antiviral activity was measured by referring to the method of
Kohase, et al. [Protein, Nucleic Acid and Enzyme (extra number), p.
335 (1981)].
That is, 5% fetal bovine serum (FBS)-supplemented Eagle's MEM was
added to a sterilized transfer plate. Then, 50 .mu.l each of
solutions of domestic standard IFN preparations [.alpha. (The Green
Cross Corporation), .beta. (Toray Industries, Inc.) and .gamma.
(The Green Cross Corporation)] were put into wells, followed by
2-fold serial dilution. On the other hand, 50 .mu.l each of
chemically modified IFNs and unmodified IFNs diluted with a medium
to predetermined concentrations were put into wells. These IFN
solutions were transferred to a 96-well plate containing a
predetermined cell number of an established cell line (FL cell)
derived from human amnion, followed by stirring for several
seconds. The resulting mixtures were incubated a whole day and
night in a CO.sub.2 incubator at 37.degree. C. to induce an
antiviral state.
Then, the culture liquors were removed, and a virus solution was
added, followed by incubation in a CO.sub.2 incubator at 37.degree.
C. for 2 days to effect viral infection. The antiviral state of the
cells was changed by IFN, and cell degeneration occurred.
Subsequently, the culture liquors were removed, and a neutral red
(NR) solution was added. The plate was allowed to stand in a
CO.sub.2 incubator at 37.degree. C. for one hour, followed by
removal of the NR solution. After the wells were washed with an
isotonic phosphate buffer, an extracting liquid (0.01 mol/l
hydrochloric acid--30% ethanol) was added, followed by stirring for
2 to 3 minutes.
The surviving cells were stained with NR. After extraction, the
absorbance at 492 nm was measured, and a standard curve was
plotted. The relative activity of each chemically modified IFN was
calculated based on the activity of the unmodified IFN calculated
from the standard curve which was defined as 100%.
The relative activity of each IFN-.beta. is shown in Tables 5 and
6.
TABLE-US-00005 TABLE 5 Antiviral activity of chemically modified
recombinant human IFN-.beta. Compound abbreviation Example Relative
activity (%) Unmodified rhIFN-.beta. -- 100 5TRC (3UA)-rhIFN-.beta.
9 58 5SKA (3UA)-rhIFN-.beta. 10 93 5PET (3UA)-rhIFN-.beta. 12
50
TABLE-US-00006 TABLE 6 Antiviral activity of chemically modified
recombinant human .sup.17Ser IFN-.beta. Compound abbreviation
Example Relative activity (%) Unmodified .sup.17Ser rhIFN-.beta. --
100 5PET (3UA)-.sup.17Ser rhIFN-.beta. 13 115
It was confirmed by the results in Tables 5 and 6 that all the
chemically modified IFN-.beta. according to the present invention
retained antiviral activity.
TEST EXAMPLE 2
Antiviral Activity of Chemically Modified Interferon-.alpha.
The antiviral activity of the chemically modified rhIFN-.alpha.
obtained in Example 14 and unmodified rhIFN-.alpha. was examined by
the NR uptake method illustrated in Test Example 1.
The activity of each IFN-.alpha. at a concentration of 1 .mu.g/ml
is shown in Table 7 (indicated as a relative activity based on the
activity of unmodified IFN-.alpha. defined as 100%).
TABLE-US-00007 TABLE 7 Antiviral activity of chemically modified
recombinant human IFN-.alpha. Compound Concentration Relative
abbreviation Example (.mu.g/ml) activity (%) Unmodified
rhIFN-.alpha. -- 1 100 5PET (3UA)-rhIFN-.alpha. 14 1 100
TEST EXAMPLE 3
Growth-promoting Activity of Chemically Modified Recombinant Human
Granulocyte-colony Stimulating Factor Derivative on Mouse Leukemia
Cell NFS60
The growth-promoting activity of the compounds of Examples 15 to
20, unmodified rhG-CSF derivative and unmodified rhG-CSF on mouse
leukemia cell NFS60 [Proc. Natl. Acad. Sci. USA, Vol. 82, p. 6687
(1985)] was measured according to the method of Asano, et al.
[Japanese Pharmacology & Therapeutics, Vol. 19, p. 2767
(1991)].
The activity of each compound at a concentration of 100 ng/ml is
shown in Tables 8 and 9 as a relative activity based on the
activity of unmodified polypeptide defined as 100%.
TABLE-US-00008 TABLE 8 NFS60 cell growth-promoting activity of
chemically modified rhG-CSF derivatives Concentration Relative
Compound abbreviation Example (ng/ml) activity (%) Unmodified
rhG-CSF deriv. -- 100 100 5SKA (3UA)-rhG-CSF deriv. 15 100 100 5QNA
(4UA)-rhG-CSF deriv. 16 100 100 5PET (3UU)-rhG-CSF deriv. 18 100
100 5PET (3UA)-rhG-CSF deriv. 19 100 100 5SUG (3UA)-rhG-CSF deriv.
20 100 100
TABLE-US-00009 TABLE 9 NFS60 cell growth-promoting activity of
chemically modified rhG-CSF Concentration Relative Compound
abbreviation Example (ng/ml) activity (%) Unmodified rhG-CSF -- 100
100 5SKA (3UA)-rhG-CSF 17 100 100
It was confirmed by the results in Tables 8 and 9 that all the
chemically modified rhG-CSF derivatives and chemically modified
rhG-CSF according to the present invention retained
growth-promoting activity on NFS60 cells.
TEST EXAMPLE 4
Enzyme Activity of Chemically Modified Superoxide Dismutase
The enzyme activity of the chemically modified SOD prepared in
Example 21 was measured by the xanthine-xanthine oxidase-cytochrome
C system of Mccord, J. M. and Fridovichi, I. [J. Biol. Chem., Vol.
244, p. 6049 (1969)]. One unit (U) of SOD activity is an enzyme
amount of SOD which inhibits the reducing rate of cytochrome C by
50% at pH 7.8 at 30.degree. C., and was calculated according to the
following equation.
.times..times..times..times..times..times..DELTA..times..times..times.
##EQU00001##
The enzyme activity of chemically modified human SOD is shown in
Table 10. SOD 50 U/ml=0.000256 mg (at 3900 U/mg) .DELTA.A/min.:
measurement result
TABLE-US-00010 TABLE 10 Enzyme activity of chemically modified
human Cu, Zn-superoxide dismutase Compound Example Relative
activity (%) Unmodified hSOD -- 100 5PET (3UM)-hSOD 21 50 *The
activity was indicated as a relative activity based on the enzyme
activity of unmodified hSOD defined as 100%.
It was confirmed by Table 10 that chemically modified hSOD
according to the present invention retained enzyme activity.
TEST EXAMPLE 5
Binding Activity of Chemically Modified Anti-GD3 Chimera
Antibody
The binding activity of the chemically modified anti-GD3 chimera
antibody (5PET(3UA)-KM871) prepared in Example 22 was measured
according to the method of Kenya. S, et al. [Cancer Immunol.
Immunother., Vol. 36, p. 373 (1993)].
The GD3-binding activity of unmodified antibody and chemically
modified anti-GD3 chimera antibody (5PET(3UA)-KM871) at a
concentration of 3.3 g/ml is shown in Table 11.
The activity was indicated as a relative activity based on the
binding activity of unmodified anti-GD3 chimera antibody defined as
100%.
TABLE-US-00011 TABLE 11 GD3-Binding activity of chemically modified
antibody Relative binding Compound Example activity (%) Unmodified
antibody -- 100 5PET (3UA)-KM871 22 86.3
It was confirmed by Table 11 that the chemically modified anti-GD3
chimera antibody (5PET(3UA)-KM871) according to the present
invention retained GD3-binding activity.
TEST EXAMPLE 6
Blood half-life Prolonging Effect of Chemically Modified
Interferon-.beta.
Each of 5TRC(3UA)-rhIFN-.beta. obtained in Example 9,
PEG.sub.2Lys-rhIFN-.beta. obtained in Reference Example 1 and
unmodified rhIFN-.beta. obtained in Reference Example 4 was
dissolved in an isotonic phosphate buffer at a concentration of
12.5 .mu.g/ml, and 200 .mu.l of each of the solutions was
intravenously injected into 8 to 10-week-old BALB/C male mice
(Charles River Japan, Inc.). At intervals, the mice were killed and
the serum was collected. The IFN-.beta. concentration in blood was
calculated by ELISA.
The result is shown in FIG. 1.
The concentration of unmodified IFN-.beta. fell below the detection
limit in one hour after the administration, whereas the
concentration of chemically modified IFN-.beta. was maintained for
several hours, showing a remarkable improvement in durability.
Moreover, the compound disclosed in the present invention, i.e.
rhIFN-.beta. modified with three-chain branched polyethylene glycol
was superior in durability in blood to rhIFN-.beta. modified with
double-chain branched polyethylene glycol, and its concentration in
blood changed at a higher level.
TEST EXAMPLE 7
Blood Half-life Prolonging Effect of Chemically Modified
rhG-CSF
Each of 5SKA(3UA)-rhG-CSF derivative obtained in Example 15,
5SKA(3UA)-rhG-CSF obtained in Example 17, PEG.sub.2Lys-rhG-CSF
derivative obtained in Reference Example 2, PEG.sub.2Lys-rhG-CSF
obtained in Reference Example 3, unmodified rhG-CSF derivative of
Reference Example 5 and unmodified rhG-CSF of Reference Example 6
was intravenously injected into male rats at a dose of 0.1 mg/kg.
At intervals, blood was collected from the tail vein. The blood was
appropriately diluted and the concentration of each compound in the
blood was measured by ELISA. The result obtained by duplicate
experiments is shown in FIG. 2.
The chemically modified G-CSFs maintained much higher concentration
in blood as compared with the unmodified G-CSFs. Moreover, it was
confirmed that the compounds disclosed in the present invention,
i.e. rhG-CSFs modified with three-chain branched polyethylene
glycol were superior in durability in blood to the compounds
modified with conventional double-chain branched polyethylene
glycol.
INDUSTRIAL APPLICABILITY
The novel polyalkylene glycols having a branched structure
disclosed in the present invention are useful as chemical modifying
reagents for physiologically active polypeptides. The
physiologically active peptides modified with the polyalkylene
glycols not only retain biological activities similar to those of
unmodified peptides, but show their physiological activities
effectively for a long time when administered into the body.
Therefore, the modified polypeptides are useful for improving or
treating clinical conditions associated with their physiological
activities.
SEQUENCE LISTINGS
1
2 1 166 PRT Hominidae 1 Met Ser Tyr Asn Leu Leu Gly Phe Leu Gln Arg
Ser Ser Asn Phe Gln 1 5 10 15 Cys Gln Lys Leu Leu Trp Gln Leu Asn
Gly Arg Leu Glu Tyr Cys Leu 20 25 30 Lys Asp Arg Met Asn Phe Asp
Ile Pro Glu Glu Ile Lys Gln Leu Gln 35 40 45 Gln Phe Gln Lys Glu
Asp Ala Ala Leu Thr Ile Tyr Glu Met Leu Gln 50 55 60 Asn Ile Phe
Ala Leu Phe Arg Gln Asp Ser Ser Ser Thr Gly Trp Asn 65 70 75 80 Glu
Thr Ile Val Glu Asn Leu Leu Ala Asn Val Tyr His Gln Ile Asn 85 90
95 His Leu Lys Thr Val Leu Glu Glu Lys Leu Glu Lys Glu Asp Phe Thr
100 105 110 Arg Gly Lys Leu Met Ser Ser Leu His Leu Lys Arg Tyr Thr
Gly Arg 115 120 125 Ile Leu His Tyr Leu Lys Ala Lys Glu Tyr Ser His
Cys Ala Trp Thr 130 135 140 Ile Val Arg Val Glu Ile Leu Arg Asn Phe
Tyr Phe Ile Asn Arg Leu 145 150 155 160 Thr Gly Tyr Leu Arg Asn 165
2 175 PRT Hominidae 2 Met Thr Pro Leu Gly Pro Ala Ser Ser Leu Pro
Gln Ser Phe Leu Leu -1 1 5 10 15 Lys Cys Leu Glu Gln Val Arg Lys
Ile Gln Gly Asp Gly Ala Ala Leu 20 25 30 Gln Glu Lys Leu Cys Ala
Thr Tyr Lys Leu Cys His Pro Glu Glu Leu 35 40 45 Val Leu Leu Gly
His Ser Leu Gly Ile Pro Trp Ala Pro Leu Ser Ser 50 55 60 Cys Pro
Ser Gln Ala Leu Gln Leu Ala Gly Cys Leu Ser Gln Leu His 65 70 75
Ser Gly Leu Phe Leu Tyr Gln Gly Leu Leu Gln Ala Leu Glu Gly Ile 80
85 90 95 Ser Pro Glu Leu Gly Pro Thr Leu Asp Thr Leu Gln Leu Asp
Val Ala 100 105 110 Asp Phe Ala Thr Thr Ile Trp Gln Gln Met Glu Glu
Leu Gly Met Ala 115 120 125 Pro Ala Leu Gln Pro Thr Gln Gly Ala Met
Pro Ala Phe Ala Ser Ala 130 135 140 Phe Gln Arg Arg Ala Gly Gly Val
Leu Val Ala Ser His Leu Gln Ser 145 150 155 Phe Leu Glu Val Ser Tyr
Arg Val Leu Arg His Leu Ala Gln Pro 160 165 170
* * * * *